A 29-year-old man who had been abroad for several years (mainly Mexico) fell ill with fever (up to 39.8 degrees C), night sweats, weight loss of 10 kg in 6 months (height 181 cm, weight 50.5 kg) and abdominal pain. Computed tomography of the abdomen revealed many enlarged abdominal lymph nodes. Serological tests were positive for HIV antibodies. Fine-needle biopsy of one of the enlarged lymph nodes revealed numerous macrophages with round inclusions, typical for Histoplasma capsulatum. Disseminated histoplasmosis was confirmed by direct antigen demonstration in serum and urine. The patient's serious clinical condition clearly improved and lymph node enlargement regressed after starting specific i.v. treatment with amphotericin B (initially 20 mg/dl, then 50 mg/dl). Although complete cure of the histoplasmosis in connection with the HIV infection is not to be expected, the patient has remained without symptoms for four months on 50 mg weekly of amphotericin B i.v., later changed to imidazole derivatives (400 mg ketoconazole or 200 mg itraconazole, respectively.