diff --git a/messages/diagnostics.md b/messages/diagnostics.md
index 50091995..e74a791a 100644
--- a/messages/diagnostics.md
+++ b/messages/diagnostics.md
@@ -14,3 +14,7 @@ The salesforcedx plugin is deprecated. Uninstall it by running: `%s plugins:unin
 # linkedPluginWarning
 
 Warning: the [%s] plugin is linked.
+
+# uninstallSuggestion
+
+Uninstall the deprecated Salesforce CLI (%s) version %s and install the @salesforce/cli version 2. See https://developer.salesforce.com/docs/atlas.en-us.sfdx_setup.meta/sfdx_setup/sfdx_setup_uninstall.htm for uninstall instructions.
diff --git a/src/diagnostics.ts b/src/diagnostics.ts
index e0cfb156..80f59e29 100644
--- a/src/diagnostics.ts
+++ b/src/diagnostics.ts
@@ -89,6 +89,27 @@ export class Diagnostics {
     });
   }
 
+  /**
+   * Checks to see if the cli is outdated and deprecated (sfdx7 sf1)
+   */
+  public async deprecatedCliCheck(): Promise<void> {
+    const cliName = this.config.name;
+    const cliVersion = this.config.version;
+
+    if (cliName === 'sfdx-cli' && cliVersion.startsWith('7.')) {
+      await Lifecycle.getInstance().emit('Doctor:diagnostic', { testName: 'using sfdx-cli version 7', status: 'fail' });
+      this.doctor.addSuggestion(messages.getMessage('uninstallSuggestion', [cliName, cliVersion]));
+    }
+
+    if (cliName === '@salesforce/cli' && cliVersion.startsWith('1.')) {
+      await Lifecycle.getInstance().emit('Doctor:diagnostic', {
+        testName: 'using @salesforce/cli version 1',
+        status: 'fail',
+      });
+      this.doctor.addSuggestion(messages.getMessage('uninstallSuggestion', [cliName, cliVersion]));
+    }
+  }
+
   /**
    * Checks if the salesforcedx plugin is installed and suggests
    * to uninstall it if there.
diff --git a/test/diagnostics.test.ts b/test/diagnostics.test.ts
index 5119c53c..5c47355b 100644
--- a/test/diagnostics.test.ts
+++ b/test/diagnostics.test.ts
@@ -86,7 +86,7 @@ describe('Diagnostics', () => {
     const results = diagnostics.run();
 
     // This will have to be updated with each new test
-    expect(results.length).to.equal(3);
+    expect(results.length).to.equal(4);
     expect(childProcessExecStub.called).to.be.true;
     expect(lifecycleEmitSpy.called).to.be.true;
     expect(lifecycleEmitSpy.args[0][0]).to.equal('Doctor:diagnostic');
@@ -204,6 +204,46 @@ describe('Diagnostics', () => {
       });
     });
   });
+  describe('deprecatedCliCheck', () => {
+    it('fails when sfdx 7 installed', async () => {
+      const dr = Doctor.init(oclifConfig);
+      const diagnostics = new Diagnostics(dr, oclifConfig);
+      await diagnostics.deprecatedCliCheck();
+
+      expect(drAddSuggestionSpy.called).to.be.true;
+      expect(lifecycleEmitSpy.called).to.be.true;
+      expect(lifecycleEmitSpy.args[0][1]).to.deep.equal({
+        testName: 'using sfdx-cli version 7',
+        status: 'fail',
+      });
+    });
+
+    it('fails when sf 1 installed', async () => {
+      oclifConfig.name = '@salesforce/cli';
+      oclifConfig.version = '1.0.0';
+      const dr = Doctor.init(oclifConfig);
+      const diagnostics = new Diagnostics(dr, oclifConfig);
+      await diagnostics.deprecatedCliCheck();
+
+      expect(drAddSuggestionSpy.called).to.be.true;
+      expect(lifecycleEmitSpy.called).to.be.true;
+      expect(lifecycleEmitSpy.args[0][1]).to.deep.equal({
+        testName: 'using @salesforce/cli version 1',
+        status: 'fail',
+      });
+    });
+
+    it('passes when sf 2 is installed', async () => {
+      oclifConfig.name = '@salesforce/cli';
+      oclifConfig.version = '2.0.0';
+      const dr = Doctor.init(oclifConfig);
+      const diagnostics = new Diagnostics(dr, oclifConfig);
+      await diagnostics.deprecatedCliCheck();
+
+      expect(drAddSuggestionSpy.called).to.be.false;
+      expect(lifecycleEmitSpy.called).to.be.false;
+    });
+  });
 
   describe('linkedPluginCheck', () => {
     it('passes when linked plugin not found', async () => {