Four cases of pleural cryptococcosis as the form of onset of cryptococcosis in patients with human immunodeficiency virus (HIV) infection are reported. In two out of the four cases cryptococci were simultaneously isolated in other localizations (blood and meninges). In the two remaining patients the pleura was the only site of the disease, with serum determination of the cryptococci antigen being negative in one. The four patients evolved favourably, with three being exclusively treated with fluconazol. Pleuritis is an infrequent manifestation in cryptococcosis although it may be the form of onset and the only localization of the disease. Only 10 cases have been reported in patients with HIV infection. The present four cases represent 11% of the authors' series of cryptococcosis in AIDS patients. The diagnostic possibility of cryptococcosis should be considered in patients with human immunodeficiency virus infection presenting pleural effusion.