diff --git a/crates/uv-resolver/src/lock/installable.rs b/crates/uv-resolver/src/lock/installable.rs
index e301cd281..86f80bc87 100644
--- a/crates/uv-resolver/src/lock/installable.rs
+++ b/crates/uv-resolver/src/lock/installable.rs
@@ -53,6 +53,43 @@ pub trait Installable<'lock> {
 
         let root = petgraph.add_node(Node::Root);
 
+        // Determine the set of activated extras and groups, from the root.
+        //
+        // TODO(charlie): This isn't quite right. Below, when we add the dependency groups to the
+        // graph, we rely on the activated extras and dependency groups, to evaluate the conflict
+        // marker. But at that point, we don't know the full set of activated extras; this is only
+        // computed below. We somehow need to add the dependency groups _after_ we've computed all
+        // enabled extras, but the groups themselves could depend on the set of enabled extras.
+        if !self.lock().conflicts().is_empty() {
+            for root_name in self.roots() {
+                let dist = self
+                    .lock()
+                    .find_by_name(root_name)
+                    .map_err(|_| LockErrorKind::MultipleRootPackages {
+                        name: root_name.clone(),
+                    })?
+                    .ok_or_else(|| LockErrorKind::MissingRootPackage {
+                        name: root_name.clone(),
+                    })?;
+
+                // Track the activated extras.
+                if dev.prod() {
+                    for extra in extras.extra_names(dist.optional_dependencies.keys()) {
+                        activated_extras.push((&dist.id.name, extra));
+                    }
+                }
+
+                // Track the activated groups.
+                for group in dist
+                    .dependency_groups
+                    .keys()
+                    .filter(|group| dev.contains(group))
+                {
+                    activated_groups.push((&dist.id.name, group));
+                }
+            }
+        }
+
         // Add the workspace packages to the queue.
         for root_name in self.roots() {
             let dist = self
@@ -77,12 +114,10 @@ pub trait Installable<'lock> {
             petgraph.add_edge(root, index, Edge::Prod(MarkerTree::TRUE));
 
             if dev.prod() {
-                // Push its dependencies on the queue and track
-                // activated extras.
+                // Push its dependencies onto the queue.
                 queue.push_back((dist, None));
                 for extra in extras.extra_names(dist.optional_dependencies.keys()) {
                     queue.push_back((dist, Some(extra)));
-                    activated_extras.push((&dist.id.name, extra));
                 }
             }
 
@@ -99,10 +134,13 @@ pub trait Installable<'lock> {
                 })
                 .flatten()
             {
-                if !dep.complexified_marker.evaluate_no_extras(marker_env) {
+                if !dep.complexified_marker.evaluate(
+                    marker_env,
+                    activated_extras.iter().copied(),
+                    activated_groups.iter().copied(),
+                ) {
                     continue;
                 }
-                activated_groups.push((&dist.id.name, group));
 
                 let dep_dist = self.lock().find_by_id(&dep.package_id);
 
diff --git a/crates/uv/tests/it/sync.rs b/crates/uv/tests/it/sync.rs
index 9f530ecd0..cc0c3267f 100644
--- a/crates/uv/tests/it/sync.rs
+++ b/crates/uv/tests/it/sync.rs
@@ -7714,3 +7714,97 @@ fn unsupported_git_scheme() -> Result<()> {
     "###);
     Ok(())
 }
+
+/// See: <https://github.com/astral-sh/uv/issues/11648>
+#[test]
+fn multiple_group_conflicts() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = []
+
+        [dependency-groups]
+        foo = [
+            "iniconfig>=2",
+        ]
+        bar = [
+            "iniconfig<2",
+        ]
+        baz = [
+            "iniconfig",
+        ]
+
+        [tool.uv]
+        conflicts = [
+          [
+            { group = "foo" },
+            { group = "bar" },
+          ],
+        ]
+        "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.sync(), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Audited in [TIME]
+    "###);
+
+    uv_snapshot!(context.filters(), context.sync().arg("--group").arg("baz"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + iniconfig==2.0.0
+    "###);
+
+    uv_snapshot!(context.filters(), context.sync().arg("--group").arg("foo").arg("--group").arg("baz"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Audited 1 package in [TIME]
+    "###);
+
+    uv_snapshot!(context.filters(), context.sync().arg("--group").arg("bar").arg("--group").arg("baz"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Uninstalled 1 package in [TIME]
+    Installed 1 package in [TIME]
+     - iniconfig==2.0.0
+     + iniconfig==1.1.1
+    "###);
+
+    uv_snapshot!(context.filters(), context.sync().arg("--group").arg("foo").arg("--group").arg("bar"), @r###"
+    success: false
+    exit_code: 2
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    error: Groups `foo` and `bar` are incompatible with the declared conflicts: {`project:foo`, `project:bar`}
+    "###);
+
+    Ok(())
+}