Four years after an HIV infection and without any preceding illness characteristic of AIDS, a 24-year-old woman developed dyspnoea on exertion and peripheral oedema. She had for several years been an intravenous drug addict and contracted hepatitis A and B. There were no symptoms of the HIV infection. Clinical, radiological and echocardiographic examination demonstrated right ventricular failure caused by pulmonary hypertension not due to pulmonary embolism or another known aetiology. The patient died suddenly 9 months after the diagnosis from heart failure. Autopsy established primary pulmonary hypertension with pathognomonic plexogenic pulmonary arterial disease which had led to cor pulmonale with overload myocarditis. Although there had been no clinical signs of renal failure, there was histological evidence of mesangioproliferative glomerulonephritis and non-destructive interstitial nephritis. This case demonstrates that, in addition to the typical AIDS-associated diseases, other rarer syndromes may, in uncertain ways but connected with the HIV infection, decide the prognosis of such patients.