One of the choppers clipped the rotor of the other before the two crashed into the ground.
The incident took place earlier today at 09:30 local time (11:30 am PNG time) in the Malaysian town of Lumut, which is home to a navy base.
There are no known survivors.
"All victims were confirmed dead on site and the remains were sent to the [Lumut] Military Hospital for identification," said the Royal Malaysian Navy (RMN).
The RMN added that it will form a committee to investigate the cause of the incident.
One of the helicopters, a HOM M503-3 with seven people on board, is believed to have crashed onto a running track.
The other, a Fennec M502-6 carrying the other three victims, crashed into a swimming pool nearby.
The state's fire and rescue department said it was alerted to the incident at 09:50 local time (11:50 am PNG time).