A 32-year woman presented at our hospital with left chest pain. Chest X-ray films revealed multiple nodular shadows (accompanied by a fusing tendency) and pleural effusion in the left lower lung field. Transbronchial lung biopsy specimens contained cryptococcal fungi. Blood and pleural effusion samples were positive for cryptococcal antigen, but cerebrospinal fluid was not. Because cryptococcus was not detected in cultures of cerebrospinal fluid, urine, or blood, and because the patient had no underlying disease, she was given a diagnosis of primary pulmonary cryptococcosis. On the second consultation 10 days later, the patient's subjective symptoms had subsided and the X-ray findings were generally improved. The condition resolved spontaneously without treatment within 4.5 months. This case is noteworthy for several reasons: (1) pleural effusion was observed, and the fluid could be examined: (2) the inflammatory reactions were pronounced at the time of first examination; and (3) the disease developed abruptly but subsided spontaneously within a short period of time. We reviewed 15 cases of primary pulmonary cryptococcosis reported recently in this journal, including this case. That review suggests that the finding concerning inflammatory reactions are associated with the motive of detection during initial examination.