We present a case in which a patient with acquired immunodeficiency syndrome (AIDS) and nocardiosis was found to have co-infection with Mycobacterium avium complex (MAC). Despite the fact that MAC is a known colonizer of the pulmonary system, it is possible to have co-infection and a high degree of suspicion is necessary to ensure prompt treatment of both organisms. We wish to describe how radiologic findings were instrumental in guiding our differential diagnosis.