diff --git a/.changeset/fix-dockerignore-validation.md b/.changeset/fix-dockerignore-validation.md
new file mode 100644
index 0000000..1630b6e
--- /dev/null
+++ b/.changeset/fix-dockerignore-validation.md
@@ -0,0 +1,5 @@
+---
+"@docker-doctor/cli": patch
+---
+
+Fix workspace discovery to correctly track and validate `.dockerignore` files, resolving false-positive warnings in the `useDockerignore` performance rule.
diff --git a/packages/core/src/project-info/discover.ts b/packages/core/src/project-info/discover.ts
index afd69a5..7a2dfa8 100644
--- a/packages/core/src/project-info/discover.ts
+++ b/packages/core/src/project-info/discover.ts
@@ -36,10 +36,15 @@ export const discoverProject = async (
   const allFiles = await walk(rootDir);
   const dockerfiles: string[] = [];
   const composeFiles: string[] = [];
+  const dockerignores: string[] = [];
 
   for (const file of allFiles) {
     const base = path.basename(file).toLowerCase();
 
+    if (base === ".dockerignore") {
+      dockerignores.push(path.relative(rootDir, file));
+    }
+
     // Match Dockerfile, Dockerfile.*, *.dockerfile
     if (
       base === "dockerfile" ||
@@ -65,5 +70,6 @@ export const discoverProject = async (
   return {
     composeFiles,
     dockerfiles,
+    dockerignores,
   };
 };
diff --git a/packages/core/src/types/index.ts b/packages/core/src/types/index.ts
index a33267a..eec85e7 100644
--- a/packages/core/src/types/index.ts
+++ b/packages/core/src/types/index.ts
@@ -18,6 +18,7 @@ export interface Diagnostic {
 export interface ProjectInfo {
   dockerfiles: string[];
   composeFiles: string[];
+  dockerignores?: string[];
 }
 
 export interface DiagnoseResult {
diff --git a/packages/docker-doctor/src/cli.ts b/packages/docker-doctor/src/cli.ts
index 5acabe0..ff76aeb 100644
--- a/packages/docker-doctor/src/cli.ts
+++ b/packages/docker-doctor/src/cli.ts
@@ -338,6 +338,25 @@ const runRulesEngine = async (
   return diagnostics;
 };
 
+const filterDiagnostics = (
+  diagnostics: Diagnostic[],
+  categories?: Record<string, RuleSeverity>
+): Diagnostic[] => {
+  if (!categories) {
+    return diagnostics;
+  }
+  return diagnostics.filter((d) => {
+    const ruleDef = findRule(d.rule);
+    if (ruleDef) {
+      const catSeverity = categories[ruleDef.category];
+      if (catSeverity === "off") {
+        return false;
+      }
+    }
+    return true;
+  });
+};
+
 const program = new Command();
 
 program
@@ -417,6 +436,7 @@ program
         const projectFilesList = [
           ...project.dockerfiles,
           ...project.composeFiles,
+          ...(project.dockerignores || []),
         ];
 
         const diagnostics = await runRulesEngine(
@@ -430,19 +450,10 @@ program
         );
 
         // Filter by category config if needed
-        let filteredDiagnostics = diagnostics;
-        if (config.categories) {
-          filteredDiagnostics = diagnostics.filter((d) => {
-            const ruleDef = findRule(d.rule);
-            if (ruleDef) {
-              const catSeverity = config.categories?.[ruleDef.category];
-              if (catSeverity === "off") {
-                return false;
-              }
-            }
-            return true;
-          });
-        }
+        const filteredDiagnostics = filterDiagnostics(
+          diagnostics,
+          config.categories
+        );
 
         // Calculate score
         const { score, label } = calculateScore(filteredDiagnostics);