No single pathophysiologic factor has been identified as the cause of recurrent acute pancreatitis. A systematic search should be undertaken in every patient to identify one of a myriad of factors that have been shown to play a part in causing this distressing illness. The abuse of alcohol remains the likeliest cause, and further research may reveal an inborn error of metabolism that jeopardizes some people. Biliary tract disease, gallstones, choledochal cyst, papillary stenosis, and duodenal diverticula show a clear relationship. Metabolic disorders such as hypercalcemia, hyperlipidemia, and hyperparathyroidism remain suspect. Systemic illnesses such as systemic lupus erythematosus and cystic fibrosis must be considered. Development anomalies such as pancreas divisum may precipitate acute pancreatitis through aberrant anatomic structures. Cancer must always be disproved. Not yet firmly established but worthy of thorough investigation are uncommon causes, such as the ingestion of certain drugs or combinations of drugs and trauma, either recent or past. Pancreatitis remains frightening for those with the disease and puzzling and frustrating for the medical people who treat it. A careful history and investigation in accordance with a systematic diagnostic plan that includes many disparate factors will lead to identification of the cause in the majority of patients.