diff --git a/sqlit/shared/ui/widgets_autocomplete.py b/sqlit/shared/ui/widgets_autocomplete.py
index 9d63f4b3..09b323f7 100644
--- a/sqlit/shared/ui/widgets_autocomplete.py
+++ b/sqlit/shared/ui/widgets_autocomplete.py
@@ -10,37 +10,40 @@
 
 class AutocompleteDropdown(VerticalScroll):
     """Dropdown widget for SQL autocomplete suggestions with scrollbar."""
-
-    DEFAULT_CSS = """
-    AutocompleteDropdown {
+    MIN_WIDTH = 25
+    MAX_WIDTH = 80
+    MAX_HEIGHT = 12
+    VERTICAL_SCROLLBAR_SIZE = 1
+    DEFAULT_CSS = f"""
+    AutocompleteDropdown {{
         layer: autocomplete;
         width: auto;
-        min-width: 25;
-        max-width: 80;
+        min-width: {MIN_WIDTH};
+        max-width: {MAX_WIDTH};
         height: auto;
-        max-height: 12;
+        max-height: {MAX_HEIGHT};
         background: $surface;
         border: round $border;
         padding: 0;
         display: none;
-        scrollbar-size: 1 1;
+        scrollbar-size: {VERTICAL_SCROLLBAR_SIZE} 1;
         constrain: inside inside;
-    }
+    }}
 
-    AutocompleteDropdown.visible {
+    AutocompleteDropdown.visible {{
         display: block;
-    }
+    }}
 
-    AutocompleteDropdown .autocomplete-item {
+    AutocompleteDropdown .autocomplete-item {{
         width: 100%;
         height: 1;
         padding: 0 1;
-    }
+    }}
 
-    AutocompleteDropdown .autocomplete-item.selected {
+    AutocompleteDropdown .autocomplete-item.selected {{
         background: $primary;
         color: $background;
-    }
+    }}
     """
 
     def __init__(self, *args: Any, **kwargs: Any) -> None:
@@ -62,6 +65,7 @@ def set_items(self, items: list[str], filter_text: str = "") -> None:
 
         self.selected_index = 0
         self._rebuild()
+        self._update_width()
         # Reset scroll to top
         self.scroll_to(y=0, animate=False)
 
@@ -124,3 +128,14 @@ def hide(self) -> None:
     def is_visible(self) -> bool:
         """Check if dropdown is visible."""
         return "visible" in self.classes
+
+    def _update_width(self) -> None:
+        """Update the width of the dropdown based on filtered items."""
+
+        width = self.MIN_WIDTH
+        if self.filtered_items:
+            padding = 6  # 2 border + 2 padding chars + 2 css padding
+            scrollbar = self.VERTICAL_SCROLLBAR_SIZE if len(self.filtered_items) > self.MAX_HEIGHT else 0
+            width = max(len(item) for item in self.filtered_items) + padding + scrollbar
+
+        self.styles.width = max(self.MIN_WIDTH, min(width, self.MAX_WIDTH))
diff --git a/tests/ui/test_autocomplete_dropdown.py b/tests/ui/test_autocomplete_dropdown.py
new file mode 100644
index 00000000..b712442b
--- /dev/null
+++ b/tests/ui/test_autocomplete_dropdown.py
@@ -0,0 +1,96 @@
+"""UI tests for autocomplete dropdown widget."""
+
+from __future__ import annotations
+
+import pytest
+from textual.app import App, ComposeResult
+
+from sqlit.shared.ui.widgets_autocomplete import AutocompleteDropdown
+
+
+class _DropdownTestApp(App):
+    """Minimal app that mounts an AutocompleteDropdown for testing."""
+
+    def compose(self) -> ComposeResult:
+        yield AutocompleteDropdown()
+
+
+class TestAutocompleteDropdownWidth:
+    """Tests for dynamic width sizing based on filtered items."""
+
+    @pytest.mark.asyncio
+    async def test_empty_items_uses_min_width(self) -> None:
+        """Width should be MIN_WIDTH when there are no filtered items."""
+        app = _DropdownTestApp()
+        async with app.run_test() as pilot:
+            dropdown = app.query_one(AutocompleteDropdown)
+            dropdown.set_items([])
+            await pilot.pause()
+
+            assert dropdown.styles.width is not None
+            assert dropdown.styles.width.value == AutocompleteDropdown.MIN_WIDTH
+
+    @pytest.mark.asyncio
+    async def test_short_items_clamped_to_min_width(self) -> None:
+        """Items shorter than MIN_WIDTH should result in width clamped to MIN_WIDTH."""
+        app = _DropdownTestApp()
+        async with app.run_test() as pilot:
+            dropdown = app.query_one(AutocompleteDropdown)
+            dropdown.set_items(["ab", "cd"])
+            await pilot.pause()
+
+            assert dropdown.styles.width is not None
+            assert dropdown.styles.width.value == AutocompleteDropdown.MIN_WIDTH
+
+    @pytest.mark.asyncio
+    async def test_width_grows_with_longer_items(self) -> None:
+        """Longer items should produce a wider dropdown than shorter items."""
+        app = _DropdownTestApp()
+        async with app.run_test() as pilot:
+            dropdown = app.query_one(AutocompleteDropdown)
+
+            dropdown.set_items(["short"])
+            await pilot.pause()
+            assert dropdown.styles.width is not None
+            width_short = dropdown.styles.width.value
+
+            dropdown.set_items(["a_much_longer_item_name_here"])
+            await pilot.pause()
+            assert dropdown.styles.width is not None
+            width_long = dropdown.styles.width.value
+
+            assert width_long > width_short
+
+    @pytest.mark.asyncio
+    async def test_long_items_clamped_to_max_width(self) -> None:
+        """Items with length exceeding MAX_WIDTH should be clamped to MAX_WIDTH."""
+        app = _DropdownTestApp()
+        async with app.run_test() as pilot:
+            dropdown = app.query_one(AutocompleteDropdown)
+            dropdown.set_items(["a" * 100])
+            await pilot.pause()
+
+            assert dropdown.styles.width is not None
+            assert dropdown.styles.width.value == AutocompleteDropdown.MAX_WIDTH
+
+    @pytest.mark.asyncio
+    async def test_scrollbar_width_added_when_items_exceed_max_height(self) -> None:
+        """Width should include scrollbar allowance when item count exceeds MAX_HEIGHT."""
+        app = _DropdownTestApp()
+        async with app.run_test() as pilot:
+            dropdown = app.query_one(AutocompleteDropdown)
+            item = "x" * 20
+
+            # Exactly MAX_HEIGHT items — no scrollbar
+            dropdown.set_items([item] * AutocompleteDropdown.MAX_HEIGHT)
+            await pilot.pause()
+            assert dropdown.styles.width is not None
+            width_at_max_height = dropdown.styles.width.value
+
+            # More than MAX_HEIGHT — scrollbar kicks in
+            dropdown.set_items([item] * (AutocompleteDropdown.MAX_HEIGHT + 1))
+            await pilot.pause()
+            assert dropdown.styles.width is not None
+            width_over_max_height = dropdown.styles.width.value
+
+            assert width_over_max_height == width_at_max_height + AutocompleteDropdown.VERTICAL_SCROLLBAR_SIZE