diff --git a/.chronus/changes/fix-lsp-fatal-logging-2026-05-28.md b/.chronus/changes/fix-lsp-fatal-logging-2026-05-28.md
new file mode 100644
index 00000000000..f00f13e5e0f
--- /dev/null
+++ b/.chronus/changes/fix-lsp-fatal-logging-2026-05-28.md
@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@typespec/compiler"
+---
+
+Language server fatal errors now write pending logs and the fatal stack trace directly to stderr so crash details remain visible.
diff --git a/packages/compiler/src/server/fatal-error.ts b/packages/compiler/src/server/fatal-error.ts
new file mode 100644
index 00000000000..d64b2342336
--- /dev/null
+++ b/packages/compiler/src/server/fatal-error.ts
@@ -0,0 +1,34 @@
+import { inspect } from "util";
+import type { ServerLog } from "./types.js";
+
+export type FatalErrorWriter = (message: string) => void;
+
+export function writeServerFatalError(
+  write: FatalErrorWriter,
+  pendingMessages: readonly ServerLog[],
+  error: unknown,
+) {
+  for (const pending of pendingMessages) {
+    write(`${formatPendingServerLog(pending)}\n`);
+  }
+  write(`${formatFatalError(error)}\n`);
+}
+
+export function formatFatalError(error: unknown): string {
+  if (error instanceof Error) {
+    return error.stack ?? `${error.name}: ${error.message}`;
+  }
+  return typeof error === "string" ? error : inspect(error);
+}
+
+function formatPendingServerLog(log: ServerLog): string {
+  const detail =
+    log.detail === undefined
+      ? undefined
+      : typeof log.detail === "string"
+        ? log.detail
+        : inspect(log.detail);
+  return detail === undefined
+    ? `[${log.level}] ${log.message}`
+    : `[${log.level}] ${log.message}:\n${detail}`;
+}
diff --git a/packages/compiler/src/server/server.ts b/packages/compiler/src/server/server.ts
index 20aa781198b..a18f5d95f85 100644
--- a/packages/compiler/src/server/server.ts
+++ b/packages/compiler/src/server/server.ts
@@ -15,16 +15,19 @@ import {
 import { NodeHost } from "../core/node-host.js";
 import { typespecVersion } from "../manifest.js";
 import { createClientConfigProvider } from "./client-config-provider.js";
+import { writeServerFatalError } from "./fatal-error.js";
 import { createServer } from "./serverlib.js";
 import { CustomRequestName, Server, ServerHost, ServerLog } from "./types.js";
 
 let server: Server | undefined = undefined;
+const writeStderr = process.stderr.write.bind(process.stderr) as (message: string) => void;
 
 const profileDir = process.env.TYPESPEC_SERVER_PROFILE_DIR;
 const logTiming = process.env.TYPESPEC_SERVER_LOG_TIMING === "true";
 let profileSession: inspector.Session | undefined;
 
 process.on("unhandledRejection", fatalError);
+process.on("uncaughtException", fatalError);
 try {
   main();
 } catch (e) {
@@ -162,12 +165,7 @@ function main() {
 function fatalError(e: unknown) {
   // If we failed to send any log messages over LSP pipe, send them to
   // stderr before exiting.
-  for (const pending of server?.pendingMessages ?? []) {
-    // eslint-disable-next-line no-console
-    console.error(pending);
-  }
-  // eslint-disable-next-line no-console
-  console.error(e);
+  writeServerFatalError(writeStderr, server?.pendingMessages ?? [], e);
   process.exit(1);
 }
 
diff --git a/packages/compiler/test/server/misc.test.ts b/packages/compiler/test/server/misc.test.ts
index 85c7b8afe75..cc01e4a892b 100644
--- a/packages/compiler/test/server/misc.test.ts
+++ b/packages/compiler/test/server/misc.test.ts
@@ -2,6 +2,7 @@ import { ok, strictEqual } from "assert";
 import { describe, it } from "vitest";
 import { SyntaxKind, TypeSpecScriptNode, parse } from "../../src/ast/index.js";
 import type { PositionDetail } from "../../src/index.js";
+import { formatFatalError, writeServerFatalError } from "../../src/server/fatal-error.js";
 import { getCompletionNodeAtPosition } from "../../src/server/serverlib.js";
 import { extractCursor } from "../../src/testing/source-utils.js";
 import { dumpAST } from "../ast-test-utils.js";
@@ -85,4 +86,25 @@ describe("compiler: server: misc", () => {
       });
     });
   });
+
+  describe("fatal error logging", () => {
+    it("writes pending server logs and fatal stack to the provided writer", () => {
+      const messages: string[] = [];
+      const error = new Error("boom");
+
+      writeServerFatalError(
+        (message) => messages.push(message),
+        [{ level: "info", message: "pending message", detail: { value: 123 } }],
+        error,
+      );
+
+      const output = messages.join("");
+      ok(output.includes("[info] pending message:\n{ value: 123 }\n"));
+      ok(output.includes("Error: boom"));
+    });
+
+    it("formats non-error fatal values", () => {
+      strictEqual(formatFatalError({ reason: "boom" }), "{ reason: 'boom' }");
+    });
+  });
 });