Abstract: A disposable air filter assembly is provided for use with, but not limited to, an internal combustion engine. The filter assembly includes a housing having a substantially spiral interior air flow passageway. The housing is of molded construction whereby the end walls thereof are initially integral with an intervening outer wall but subsequently a section of one of the end walls is severed from the remainder of the housing exposing the interior passageway. A filter member, conforming substantially to the configuration of at least a portion of the passageway is inserted therein. Subsequent to the filter member being inserted into the passageway, the separated end wall section is re-attached to the remainder of the housing. An inlet to the interior passageway is provided on the exterior of the housing whereby the air flow is in a substantially tangential direction. An outlet for the passageway downstream of the inlet is provided which communicates with the intake manifold of the engine.