Delta flight DL850, which was traveling from Hartsfield-Jackson International Airport in Atlanta to Ronald Reagan Washington National Airport in Virginia, was diverted to RDU out of an abundance of caution.
Delta officials said there was a reported odor in the flight deck, according to Delta officials.
Multiple emergency vehicles could be seen at the scene checking on the plane.
Officials said 150 passengers and six crew members were removed from the plane and moved to a new aircraft that's expected to resume their trip to Arlington.
"Safety is always our top priority, and we apologize to our customers for the delay in their travels," Delta told ABC Raleigh affiliate WTVD.
No injuries were reported.
The Federal Aviation Administration is now investigating what happened.