A heat dissipating fan includes a frame, a first rotor having a shaft and a hub, a base disposed in the frame, a second rotor disposed at one side of the first rotor and coupled to the first rotor, and a driving element supported by the base for driving the first and second rotors to rotate. The hubs of the first and second rotors include a plurality of heat dissipating holes formed on the surface thereof. Airflow passes through the plurality of heat dissipating holes to generate a forced convection effect on the driving element.