diff --git a/experimental/CHANGELOG.md b/experimental/CHANGELOG.md
index 4fa6f675390..c1762a1da63 100644
--- a/experimental/CHANGELOG.md
+++ b/experimental/CHANGELOG.md
@@ -29,6 +29,8 @@ All notable changes to experimental packages in this project will be documented
 
 ### :house: (Internal)
 
+* refactor(otlp-exporter-base): remove unnecessary isNaN() checks [#5374](https://github.com/open-telemetry/opentelemetry-js/pull/5374) @cjihrig
+
 ## 0.57.0
 
 ### :rocket: (Enhancement)
diff --git a/experimental/packages/otlp-exporter-base/src/configuration/shared-configuration.ts b/experimental/packages/otlp-exporter-base/src/configuration/shared-configuration.ts
index d9d589e3699..c771cc07678 100644
--- a/experimental/packages/otlp-exporter-base/src/configuration/shared-configuration.ts
+++ b/experimental/packages/otlp-exporter-base/src/configuration/shared-configuration.ts
@@ -29,11 +29,7 @@ export interface OtlpSharedConfiguration {
 }
 
 export function validateTimeoutMillis(timeoutMillis: number) {
-  if (
-    !Number.isNaN(timeoutMillis) &&
-    Number.isFinite(timeoutMillis) &&
-    timeoutMillis > 0
-  ) {
+  if (Number.isFinite(timeoutMillis) && timeoutMillis > 0) {
     return timeoutMillis;
   }
   throw new Error(
diff --git a/experimental/packages/otlp-exporter-base/src/configuration/shared-env-configuration.ts b/experimental/packages/otlp-exporter-base/src/configuration/shared-env-configuration.ts
index 767ec05f4a8..d91b4417b57 100644
--- a/experimental/packages/otlp-exporter-base/src/configuration/shared-env-configuration.ts
+++ b/experimental/packages/otlp-exporter-base/src/configuration/shared-env-configuration.ts
@@ -22,11 +22,7 @@ function parseAndValidateTimeoutFromEnv(
   const envTimeout = process.env[timeoutEnvVar]?.trim();
   if (envTimeout != null && envTimeout !== '') {
     const definedTimeout = Number(envTimeout);
-    if (
-      !Number.isNaN(definedTimeout) &&
-      Number.isFinite(definedTimeout) &&
-      definedTimeout > 0
-    ) {
+    if (Number.isFinite(definedTimeout) && definedTimeout > 0) {
       return definedTimeout;
     }
     diag.warn(
diff --git a/experimental/packages/otlp-exporter-base/test/common/configuration/shared-configuration.test.ts b/experimental/packages/otlp-exporter-base/test/common/configuration/shared-configuration.test.ts
index 413ec5e5e6a..b2439c01f06 100644
--- a/experimental/packages/otlp-exporter-base/test/common/configuration/shared-configuration.test.ts
+++ b/experimental/packages/otlp-exporter-base/test/common/configuration/shared-configuration.test.ts
@@ -19,6 +19,7 @@ import {
   mergeOtlpSharedConfigurationWithDefaults,
   OtlpSharedConfiguration,
 } from '../../../src';
+import { validateTimeoutMillis } from '../../../src/configuration/shared-configuration';
 
 export function testSharedConfigBehavior<T extends OtlpSharedConfiguration>(
   sut: (
@@ -134,3 +135,15 @@ describe('mergeOtlpSharedConfigurationWithDefaults', function () {
     concurrencyLimit: 2,
   });
 });
+
+describe('validateTimeoutMillis', function () {
+  it('throws if timeout is not a positive number', () => {
+    const values = [null, '1', true, NaN, Infinity, -Infinity, -1, 0];
+
+    for (let i = 0; i < values.length; ++i) {
+      assert.throws(() => {
+        validateTimeoutMillis(values[i] as any);
+      }, /Configuration: timeoutMillis is invalid/);
+    }
+  });
+});