Cannabinoid hyperemesis syndrome (CHS) characterized by cyclic vomiting after chronic cannabis exposure has beenincreasingly reported but still less-appreciated with acute renal failure. An otherwise healthy 50-year-old man manifestedvigorous vomiting with severe acute renal failure and metabolic alkalosis in the emergency department repetitively.Without receiving hemodialysis, all of his clinical symptoms and abnormal laboratory fi ndings completely resolved afteraggressive volume repletion, electrolyte supplementation, and control of vomiting. There was no ascertainable etiologyfor vomiting after serial laboratory and radiological workups. Based on his positive urine toxicology screening for tetrahydrocannabinol,an ill-concealed history of cannabis smoking, and the behavior of compulsive and prolonged hot springbaths alleviating the intractable vomiting, he was believed to have CHS. Repetitive vomiting and acute renal failure maybe the presenting feature of CHS. Early recognition of CHS with prompt treatment is crucial to avoid futile examinationsand inappropriate management, and to hasten cannabis cessation.