A 73-year-old man was admitted to hospital suffering from organophosphate intoxication. On the fourth day of admission, his serum amylase level was elevated (1, 713IU/l), in accordance with a marked elevation in his serum pancreatic phospholipase A₂ (PLA₂) and elastase-1 levels. A diagnosis of acute pancreatitis was made based on the results of an abdominal computed tomography (CT) examination, which revealed edematous swelling in the head of the pancreas. The organophosphate intoxication likely produced an excessive cholinergic effect, inducing a functional obstruction in the pancreatic duct and hyperstimulation of the acinar cells immediately after organophosphate loading. These two effects are likely to have caused the interstitial pancreatitis. The CT findings in this case seem to support this mechanism. The patient's pancreatitis, which occurred soon after hospitalization, improved after several days. Some reports have described the occurrence of necrotizing pancreatitis in cases of organophosphate intoxication. The occurrence of pancreatic involvement in association with organophosphate intoxication is much higher than previously thought, and other serum pancreatic enzymes, in addition to amylase, should be measured shortly after admission. When pancreatitis occurs, proper treatment should be applied according to the severity of the condition.