A 52-year old male homosexual patient with acquired immunodeficiency syndrome (AIDS) presented in our clinic with multiple nodular papules (more than 100) spread over the whole body which had developed within 3 months. Bacillary angiomatosis was suspected, which is a bacterial infectious disease recognized recently mainly in patients with AIDS. Histological and immunohistochemical examinations of extirpated skin lesions were in agreement with the diagnosis, and the detection of rod-shaped bacteria in the lesions by Warthin-Starry silver stain confirmed it. The patient was treated with 2 x 100 mg doxycycline per day. The fever disappeared, and the cutaneous lesions showed a slight tendency to improve. However, after 5 days of therapy the patient showed increasing weakness, with muscle and bone pain. The patient died 10 days after the doxycycline therapy had been started. The cutaneous lesions in bacillary angiomatosis may resemble Kaposi's sarcoma and may therefore be misdiagnosed. The disease may be fatal, but timely antibiotic treatment is usually effective; therefore, the diagnosis of bacillary angiomatosis is important. Although many cases have been reported from the United States, only one case is known from Europe. Our finding of bacillary angiomatosis in a German AIDS patient supports the concept of a worldwide distribution of this bacterial agent.