Postacne osteoma cutis is a rare complication of acne vulgaris. If it occurs during a course of tetracycline or minocycline therapy, pigmented osteomas can occur as a result of tetracycline or minocycline bone complexes. We report a case of pigmented postacne osteoma cutis that developed after extensive acne surgery and a 2- to 3-month course of minocycline. Previously reported cases have been treated surgically, but our patient responded to 0.05% tretinoin cream, with transepidermal elimination of some osteomas. © 1991, American Academy of Dermatology, Inc.. All rights reserved.