This report describes a case of rapidly progressive periodontal tissue breakdown and bone loss in an HIV-infected markedly immunosuppressed homosexual male. Within 6 months of initial presentation with a necrotizing ulcerative gingivitis, the lesion extended to a necrotizing ulcerative stomatitis involving the surrounding periodontium and palatal mucosa. With only partial compliance to local debridement, chlorhexidine oral rinses, and systemic metronidazole therapy, alveolar bone loss resulted in tooth mobility necessitating extraction of 2 involved teeth. This case illustrates the continuum of necrotizing ulcerative infections of the periodontium in the severely immunosuppressed patient. The implications of these oral manifestations of HIV infection are discussed.