diff --git a/assets/css/basic.css b/assets/css/basic.css
index b323e0e0..92e1b943 100644
--- a/assets/css/basic.css
+++ b/assets/css/basic.css
@@ -425,6 +425,11 @@ body {
 .dropdown-menu.show {
     display: block;
 }
+/* Anchors the menu's right edge to the button's right edge, so it opens inwards. */
+.dropdown-menu-end {
+    left: auto;
+    right: 0;
+}
 
 /* Options and headers stay on one line, so the menu grows to fit the longest one. */
 .dropdown-item {
diff --git a/extensions/pagetop-bootsier/src/theme/bs/dropdown.rs b/extensions/pagetop-bootsier/src/theme/bs/dropdown.rs
index 829f0f24..f988605f 100644
--- a/extensions/pagetop-bootsier/src/theme/bs/dropdown.rs
+++ b/extensions/pagetop-bootsier/src/theme/bs/dropdown.rs
@@ -56,6 +56,11 @@ pub trait DropdownBootsier {
     fn with_direction(self, direction: Direction) -> Self;
 
     /// Configura la alineación horizontal (con posible comportamiento *responsive* adicional).
+    ///
+    /// Si se deja en [`MenuAlign::Start`] (por defecto), se respeta [`with_menu_end()`]; cualquier
+    /// otra alineación prevalece sobre él.
+    ///
+    /// [`with_menu_end()`]: pagetop::base::component::Dropdown::with_menu_end
     fn with_menu_align(self, align: MenuAlign) -> Self;
 
     /// Configura la posición del menú.
@@ -135,9 +140,15 @@ pub(crate) async fn render(
     let direction = dropdown
         .props()
         .extra_or(EXTRA_DIRECTION, Direction::default());
-    let menu_align = dropdown
+    let menu_align = match dropdown
         .props()
-        .extra_or(EXTRA_MENU_ALIGN, MenuAlign::default());
+        .extra_or(EXTRA_MENU_ALIGN, MenuAlign::default())
+    {
+        // `with_menu_end()` del núcleo se traduce a `MenuAlign::End`, pero sólo si no hay una
+        // alineación propia diferente a la predeterminada (`Start`), que prevalece.
+        MenuAlign::Start if *dropdown.menu_end() => MenuAlign::End,
+        align => align,
+    };
     let menu_position = dropdown
         .props()
         .extra_or(EXTRA_MENU_POSITION, MenuPosition::default());
diff --git a/extensions/pagetop-bootsier/src/theme/bs/nav.rs b/extensions/pagetop-bootsier/src/theme/bs/nav.rs
index 5567bef9..90373526 100644
--- a/extensions/pagetop-bootsier/src/theme/bs/nav.rs
+++ b/extensions/pagetop-bootsier/src/theme/bs/nav.rs
@@ -169,6 +169,11 @@ pub(crate) async fn item_render(item: &Item, cx: &mut Context) -> Result<Markup,
                         .lookup(cx)
                         .unwrap_or_else(|| "Dropdown".to_string())
                 });
+                let menu_classes = if *dd.menu_end() {
+                    "dropdown-menu dropdown-menu-end"
+                } else {
+                    "dropdown-menu"
+                };
                 html! {
                     li (item.props().unpack(cx)) {
                         a
@@ -181,7 +186,7 @@ pub(crate) async fn item_render(item: &Item, cx: &mut Context) -> Result<Markup,
                         {
                             (title)
                         }
-                        ul class="dropdown-menu" {
+                        ul class=(menu_classes) {
                             (items)
                         }
                     }
diff --git a/extensions/pagetop-bootsier/tests/breakpoint_class.rs b/extensions/pagetop-bootsier/tests/breakpoint_class.rs
index cdadbec0..715280b0 100644
--- a/extensions/pagetop-bootsier/tests/breakpoint_class.rs
+++ b/extensions/pagetop-bootsier/tests/breakpoint_class.rs
@@ -63,6 +63,59 @@ async fn dropdown_menu_align_combines_breakpoint_classes() {
     );
 }
 
+async fn dropdown_menu_html(dropdown: bs::Dropdown) -> String {
+    let mut dropdown = dropdown
+        .with_title(Lc::n("Menu"))
+        .with_item(bs::dropdown::Item::link(Lc::n("Home"), "/"));
+    dropdown.render(&mut cx()).await.into_string()
+}
+
+#[pagetop::test]
+async fn dropdown_menu_end_maps_to_the_end_alignment() {
+    let html = dropdown_menu_html(bs::Dropdown::new().with_menu_end(true)).await;
+    assert!(html.contains(r#"<ul class="dropdown-menu dropdown-menu-end">"#));
+
+    // Without `with_menu_end()` the menu keeps the default (start) alignment.
+    let html = dropdown_menu_html(bs::Dropdown::new()).await;
+    assert!(html.contains(r#"<ul class="dropdown-menu">"#));
+    assert!(!html.contains("dropdown-menu-end"));
+}
+
+#[pagetop::test]
+async fn dropdown_menu_end_is_ignored_without_title() {
+    // A titleless menu is static (no button to align to), so it never gets the end alignment.
+    let mut dropdown = bs::Dropdown::new()
+        .with_menu_end(true)
+        .with_item(bs::dropdown::Item::link(Lc::n("Home"), "/"));
+    let html = dropdown.render(&mut cx()).await.into_string();
+    assert!(html.contains(r#"<ul class="dropdown-menu">"#));
+    assert!(!html.contains("dropdown-menu-end"));
+}
+
+#[pagetop::test]
+async fn dropdown_own_menu_align_wins_over_menu_end() {
+    let html = dropdown_menu_html(
+        bs::Dropdown::new()
+            .with_menu_end(true)
+            .with_menu_align(bs::dropdown::MenuAlign::StartAt(Breakpoint::Md)),
+    )
+    .await;
+    assert!(html.contains("dropdown-menu-md-start"));
+    assert!(!html.contains("dropdown-menu-end"));
+}
+
+#[pagetop::test]
+async fn nav_dropdown_menu_end_adds_the_end_class() {
+    let mut nav = bs::Nav::new().with_item(bs::nav::Item::dropdown(
+        bs::Dropdown::new()
+            .with_title(Lc::n("Menu"))
+            .with_menu_end(true)
+            .with_item(bs::dropdown::Item::link(Lc::n("Home"), "/")),
+    ));
+    let html = nav.render(&mut cx()).await.into_string();
+    assert!(html.contains(r#"<ul class="dropdown-menu dropdown-menu-end">"#));
+}
+
 #[pagetop::test]
 async fn navbar_expands_at_md_by_default_and_at_the_chosen_breakpoint() {
     let item =
diff --git a/src/base/component/dropdown/component.rs b/src/base/component/dropdown/component.rs
index dad4b5d4..5de952ee 100644
--- a/src/base/component/dropdown/component.rs
+++ b/src/base/component/dropdown/component.rs
@@ -37,6 +37,8 @@ pub struct Dropdown {
     /// Devuelve el estilo visual del botón.
     #[getters(copy)]
     button_style: button::Style,
+    /// Devuelve si el menú se alinea al final del botón (por defecto, al inicio).
+    menu_end: bool,
     /// Devuelve la lista de elementos del menú.
     items: Children,
 }
@@ -124,12 +126,23 @@ impl Component for Dropdown {
                         (&title)
                     }
                 }
-                ul class="dropdown-menu" { (items) }
+                ul class=(self.menu_classes()) { (items) }
             }
         })
     }
 }
 
+impl Dropdown {
+    // Clases del `<ul>` del menú, compartidas con el renderizado de `nav::Item::dropdown()`.
+    pub(crate) fn menu_classes(&self) -> &'static str {
+        if *self.menu_end() {
+            "dropdown-menu dropdown-menu-end"
+        } else {
+            "dropdown-menu"
+        }
+    }
+}
+
 #[builder_impl]
 impl Dropdown {
     // **< Dropdown BUILDER >***********************************************************************
@@ -170,6 +183,16 @@ impl Dropdown {
         self
     }
 
+    /// Alinea el menú al final del botón (por defecto, al inicio).
+    ///
+    /// Útil cuando el desplegable está pegado al borde final de la página, p. ej. el último de una
+    /// [`Navbar`], para que el menú se abra hacia el interior y no se salga de la pantalla. No
+    /// tiene efecto en un menú sin título, que es estático y no tiene botón al que alinearse.
+    pub fn with_menu_end(mut self, end: bool) -> Self {
+        self.menu_end = end;
+        self
+    }
+
     /// Añade un nuevo elemento al menú o modifica la lista de elementos del menú con una operación
     /// [`TypedOp`].
     ///
diff --git a/src/base/component/nav/item.rs b/src/base/component/nav/item.rs
index 7c1d9c85..8b0391f5 100644
--- a/src/base/component/nav/item.rs
+++ b/src/base/component/nav/item.rs
@@ -163,7 +163,7 @@ impl Component for Item {
                             {
                                 (title)
                             }
-                            ul class="dropdown-menu" {
+                            ul class=(dd.menu_classes()) {
                                 (items)
                             }
                         }
diff --git a/tests/component_dropdown.rs b/tests/component_dropdown.rs
new file mode 100644
index 00000000..05ff49f7
--- /dev/null
+++ b/tests/component_dropdown.rs
@@ -0,0 +1,50 @@
+use pagetop::prelude::*;
+
+fn dropdown() -> Dropdown {
+    Dropdown::new()
+        .with_title(Lc::n("Menu"))
+        .with_item(dropdown::Item::link(Lc::n("Home"), "/"))
+}
+
+#[pagetop::test]
+async fn menu_is_aligned_to_the_start_by_default() {
+    let html = dropdown()
+        .render(&mut Context::default())
+        .await
+        .into_string();
+
+    assert!(html.contains(r#"<ul class="dropdown-menu">"#));
+    assert!(!html.contains("dropdown-menu-end"));
+}
+
+#[pagetop::test]
+async fn menu_end_adds_the_end_class() {
+    let html = dropdown()
+        .with_menu_end(true)
+        .render(&mut Context::default())
+        .await
+        .into_string();
+
+    assert!(html.contains(r#"<ul class="dropdown-menu dropdown-menu-end">"#));
+}
+
+#[pagetop::test]
+async fn menu_end_applies_to_a_dropdown_inside_a_nav() {
+    let mut nav = Nav::new().with_item(nav::Item::dropdown(dropdown().with_menu_end(true)));
+    let html = nav.render(&mut Context::default()).await.into_string();
+
+    assert!(html.contains(r#"<ul class="dropdown-menu dropdown-menu-end">"#));
+}
+
+#[pagetop::test]
+async fn menu_end_is_ignored_without_title() {
+    let html = Dropdown::new()
+        .with_menu_end(true)
+        .with_item(dropdown::Item::link(Lc::n("Home"), "/"))
+        .render(&mut Context::default())
+        .await
+        .into_string();
+
+    assert!(html.contains(r#"<ul class="dropdown-menu">"#));
+    assert!(!html.contains("dropdown-menu-end"));
+}