We studied 6 men who had some combination of dyspnea, abnormal chest radiographs, resting increased alveolar-arterial oxygen gradients, noncaseating granuloma by lung biopsies, increased serum angiotensin-converting enzyme concentrations, positive gallium lung scans, and increased lymphocyte counts by bronchoalveolar lavage. Our patients were suffering from talc granulomatosis secondary to the intravenous injection of suspended, crushed pentazocine tablets. In addition to the above findings, bronchoalveolar lavage revealed birefringent intracellular and extracellular particles consistent with talc. We conclude that talc granulomatosis can mimic the laboratory findings of pulmonary sarcoidosis, but the findings of birefringent particles in the bronchoalveolar lavage fluid by polarized microscopy is a simple laboratory method for confirming a clinical diagnosis.