A ventilation apparatus of a lamp module for vehicles may include: a lamp housing; a lamp emitting light through a light transmitting part; a light transmitting lens covering an opening of the lamp housing; an intake hole part formed through the lamp housing, and arranged at one side of the lamp; an exhaust hole part formed through the lamp housing, and arranged at the other side of the lamp; and an exhaust pipe having one side coupled to the lamp housing and connected to the exhaust hole part and the other side connected to an intake part of an engine.