A 56-year-old male attempted suicide by ingestion of about 60 ml of 50% fenitrothion (Sumithion) emulsion. Five hours later, combined hemoperfusion and hemodialysis (HP-HD) treatment was performed for 60 min and consequently the toxic symptoms improved gradually. However, cholinergic symptoms recurred 4 days after ingestion. Although HP-HD was immediately performed for 180 min, it had no effect on the clinical symptoms. He died of respiratory insufficiency 6 days after the ingestion of fenitrothion.Fenitrothion concentration in the organs and tissues showed the highest values in the fat tissue, followed in decreasing order by the pancreas, muscle, lung and brain. The results indicate that fenitrothion has high lipid solubility and deposits in the fat tissue. Furthermore, we believe that when HP-HD therapy is used in the treatment of acute insecticide poisoning it is important that it be performed continuously and in as early a stage as possible.