Cases of acquired immune deficiency syndrome (AIDS) continue to be reported at an alarming rate. As the numbers of cases increase, so too does the list of unusual manifestations associated with this syndrome. We report here a patient with AIDS who, during his clinical course, had a previously undescribed, histologically atypical, subcutaneous infection develop. Light microscopic, electron microscopic, and microbiologic data are presented. The cause and pathogenesis of this lesion are discussed.