Two pilots, the only two people on board, received injuries that were not life-threatening, fire officials said.
One plane was taking off and the other was landing on a crossing runway when the planes collided, said Donn Walker, spokesman for the Federal Aviation Administration in Los Angeles.
One plane flipped and the other remained upright. Both caught fire, but neither pilot was burned, said Terri Tarbett, assistant North Las Vegas fire chief.
The pilots were not identified, and a spokeswoman for University Medical Center in Las Vegas said she could not release information about their conditions.
The airport, about 10 miles northwest of the Las Vegas Strip, serves primarily small planes, but is one of the 55 busiest in the nation.
The FAA reported in August that it had more ``runway incursions'' from 1999 to 2002 than any other airport in the nation except Los Angeles International Airport. An incursion is when an aircraft, vehicle or person is someplace they shouldn't be on a taxiway or runway.
The FAA and National Transportation Safety Board were investigating.
