A US McDonald's employee who was caught with his hands down his pants while working in the kitchen has been fired.

Customer John Holieb snapped the un-uniformed employee engaging in the disgusting act when he and his girlfriend reached the window of the Pittsburgh drive-thru.

"My girlfriend made a comment about how she can't believe no one is wearing uniforms. Then she notices the guy with both hands down his pants," he told Fox News.

"I looked and said, 'WTF. This is crazy'. There was a few of them just standing there talking. Then I reached for my phone and took two pictures."


Holieb then posted the photos on social media which promoted a woman, who claimed to be the general manager of the branch, to send him a message.

"Good morning. My name is Kara. I am the (general manager) of the restaurant from your post," the message reads.

"I just wanted to let you know that I had some employees send me your post this morning and wanted to let you know that the matter has been corrected immediately.

"I work hard to keep food safety as my top priority and I continue to do so. Please know that the owner and I have taken action."

A McDonald's spokesperson confirmed to Fox News that the company that owns the franchise took immediate action as soon as they were made aware of the incident.

They said that they had fired the employee and that "providing safe, high-quality food is a top priority."