Two patients had many acute episodes of biliary pain with elevated liver function tests 12-48 h after the last ingestion of nonsteroidal anti-inflammatory drugs (NSAIDs) (including paracetamol) alone or in combination with codeine. One had known intolerance to NSAIDs, but paracetamol had not been previously incriminated in the pathogenesis of the attacks. In this patient the combined use of paracetamol and codeine probably also increased the severity of the episodes. We conclude that in some patients in whom endoscopic cholangiography is normal, biliary pain and abnormal liver function tests could be the result of NSAIDs. A thorough drug history is required in such cases.