Two histochemical staining methods, eosine-methylene blue fast (RAL 555) and silver methenamine (modified Grocott's technique), and indirect immunofluorescence assay with an anticyst monoclonal antibody were used to detect Pneumocystis carinii in the broncho-alveolar lavage fluid and induced sputum from 58 HIV+ patients. Immunofluorescence disclosed the largest number of carriers (35 p. cent of examined patients). However, the histochemical staining techniques remain of interest and are the initial method of choice. They are inexpansive and rapid to achieve; less sensitive than immunofluorescence, positive results argue a high enough level of parasitism which leads to clinical manifestations. The increased sensitivity of immunofluorescence has considerably improved the ability to detect Pneumocystis in induced sputum. It allowed us to disclose 18 out 20 carriers (90 p. cent). However when a Pneumocystis is suspected, it is preferable to sample bronchoalveolar lavage fluid. Its examination is quick, easy and quantitative appreciation of results bring important diagnostic arguments. Other parasites, such as toxoplasmas, may also be detected. On the other hand, the examination of expectoration is time consuming and difficult to read and interpret. Therefore, sputum induction for the diagnosis of Pneumocystosis should be reserved to unequiped centers or insufficiently equiped centers (i.e., devoid of intensive care units).