Pulmonary embolism from metallic mercury is rare. It may occur after a deliberate intravenous injection of mercury as a suicide gesture, in the presence of drug abuse or severe psychiatric disturbance, with the hope of increasing athletic and sexual performance, and accidentally during right heart catheterization while sampling blood with mercury containing syringes. We have experienced the first case of pulmonary embolism associated with intravenous mercury injection in Korea. The blood mercury level remain elevated within the toxic range to date. This may be due to the continued absorption of embolized mercury. Multifocal areas of patchy perfusion defects are in both upper lung fields on perfusion scan of lung. Few of the abnormalities of respiratory or renal function reported previously were demonstrated. We report the case of a young male patient presenting with a clinical picture of pulmonary embolism, in whom widespread deposit of metallic mercury were demonstrated throughout both lungs and elsewhere in the body.