diff --git a/src/routes/cases.index.tsx b/src/routes/cases.index.tsx
index 8d93c6b..70d7093 100644
--- a/src/routes/cases.index.tsx
+++ b/src/routes/cases.index.tsx
@@ -13,8 +13,9 @@ import { formatDate, statusBadgeClass } from "@/lib/format";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 import { setArchived } from "@/lib/archive";
 import { NewCaseDialog } from "@/components/cases/new-case-dialog";
+import { formatDistanceToNow } from "date-fns";
 
-type SortKey = "title" | "client" | "status" | "attorney" | "opened_at";
+type SortKey = "title" | "client" | "status" | "attorney" | "opened_at" | "last_activity";
 type SortDir = "asc" | "desc";
 
 export const Route = createFileRoute("/cases/")({
@@ -32,15 +33,58 @@ function CasesList() {
   const [statusFilter, setStatusFilter] = useState<string>("all");
   const [view, setView] = useState<"active" | "archived">("active");
   const [newOpen, setNewOpen] = useState(false);
-  const [sortKey, setSortKey] = useState<SortKey>("title");
-  const [sortDir, setSortDir] = useState<SortDir>("asc");
+  const [sortKey, setSortKey] = useState<SortKey>("last_activity");
+  const [sortDir, setSortDir] = useState<SortDir>("desc");
 
   const load = async () => {
-    const { data } = await supabase
+    const { data: caseRows } = await supabase
       .from("cases")
       .select("*, client:clients(name), assignee:profiles!cases_assigned_attorney_id_fkey(full_name, email)")
       .order("updated_at", { ascending: false });
-    setCases(data ?? []);
+
+    const baseRows = caseRows ?? [];
+
+    // Aggregate latest activity from related child tables.
+    const [
+      tasksRes, timeRes, expensesRes, docsRes, callRes,
+      commentsRes, invoicesRes, eventsRes,
+    ] = await Promise.all([
+      supabase.from("tasks").select("case_id, updated_at").not("case_id", "is", null).limit(20000),
+      supabase.from("time_entries").select("case_id, updated_at").limit(20000),
+      supabase.from("expenses").select("case_id, updated_at").limit(20000),
+      supabase.from("documents").select("case_id, created_at").limit(20000),
+      supabase.from("call_logs").select("case_id, updated_at").limit(20000),
+      supabase.from("comments").select("case_id, created_at").not("case_id", "is", null).limit(20000),
+      supabase.from("invoices").select("case_id, updated_at").not("case_id", "is", null).limit(20000),
+      supabase.from("events").select("case_id, updated_at").not("case_id", "is", null).limit(20000),
+    ]);
+
+    const latest: Record<string, string> = {};
+    const ingest = (rows: any[] | null | undefined, field: "updated_at" | "created_at") => {
+      for (const r of rows ?? []) {
+        const cid = r.case_id as string | null;
+        const ts = r[field] as string | null;
+        if (!cid || !ts) continue;
+        if (!latest[cid] || ts > latest[cid]) latest[cid] = ts;
+      }
+    };
+    ingest(tasksRes.data, "updated_at");
+    ingest(timeRes.data, "updated_at");
+    ingest(expensesRes.data, "updated_at");
+    ingest(docsRes.data, "created_at");
+    ingest(callRes.data, "updated_at");
+    ingest(commentsRes.data, "created_at");
+    ingest(invoicesRes.data, "updated_at");
+    ingest(eventsRes.data, "updated_at");
+
+    // Fallback to the case's own updated_at if no child activity found.
+    const enriched = baseRows.map((c: any) => {
+      const childTs = latest[c.id];
+      const lastActivity = childTs && (!c.updated_at || childTs > c.updated_at) ? childTs : c.updated_at;
+      return { ...c, last_activity: lastActivity };
+    });
+
+    setCases(enriched);
   };
 
   useEffect(() => {
@@ -64,6 +108,7 @@ function CasesList() {
         case "status": return (c.status ?? "").toLowerCase();
         case "attorney": return (c.assignee?.full_name || c.assignee?.email || "").toLowerCase();
         case "opened_at": return c.opened_at ?? "";
+        case "last_activity": return c.last_activity ?? "";
       }
     };
     const arr = [...filtered];
@@ -82,7 +127,7 @@ function CasesList() {
       setSortDir(sortDir === "asc" ? "desc" : "asc");
     } else {
       setSortKey(key);
-      setSortDir(key === "opened_at" ? "desc" : "asc");
+      setSortDir(key === "opened_at" || key === "last_activity" ? "desc" : "asc");
     }
   };
 
@@ -158,12 +203,13 @@ function CasesList() {
                 <SortHeader label="Status" k="status" />
                 <SortHeader label="Attorney" k="attorney" />
                 <SortHeader label="Opened" k="opened_at" />
+                <SortHeader label="Last activity" k="last_activity" />
                 <th className="text-right px-4 py-3 font-medium w-12"></th>
               </tr>
             </thead>
             <tbody>
               {sorted.length === 0 && (
-                <tr><td colSpan={6} className="text-center py-12 text-muted-foreground">
+                <tr><td colSpan={7} className="text-center py-12 text-muted-foreground">
                   {view === "archived" ? "No archived cases." : "No cases."}
                 </td></tr>
               )}
@@ -190,6 +236,9 @@ function CasesList() {
                   </td>
                   <td className="px-4 py-3 text-muted-foreground">{c.assignee?.full_name || c.assignee?.email || "—"}</td>
                   <td className="px-4 py-3 text-muted-foreground">{formatDate(c.opened_at)}</td>
+                  <td className="px-4 py-3 text-muted-foreground" title={c.last_activity ? new Date(c.last_activity).toLocaleString() : ""}>
+                    {c.last_activity ? `${formatDistanceToNow(new Date(c.last_activity))} ago` : "—"}
+                  </td>
                   <td className="px-4 py-3 text-right" onClick={(e) => e.stopPropagation()}>
                     <Button
                       size="icon"