A heat dissipating fan includes a housing having an air inlet and an air outlet between which an air passageway is formed. A fixed seat is provided in the air passageway and includes first positioning holes. A magnetically conductive first casing includes a first outer wall, an extended wall extending radially outward from an end of the first outer wall and having second positioning holes aligned with the first positioning holes, and a first support on the other end of the first outer wall. A second casing is coupled to an inner periphery of the extended wall of the first casing. A motor mounted in the first and second casings includes a stator and a circuit board electrically connected to the stator.