A cyclist has been killed in a collision with a truck during peak hour in Rose Bay in Sydney's eastern suburbs, paramedics say.

The crash occurred on New South Head Road, near the intersection with Kent Road, about 7.45am on Thursday.

A NSW Ambulance spokeswoman said paramedics were called following reports that a male cyclist, thought to be aged in his 50s, had been seriously injured in a crash with a truck and was still trapped under the vehicle.

The man died at the scene of the crash, the spokeswoman confirmed.