Meperidine is a widely prescribed opioid analgesic used in a variety of clinical situations. The parent compound has central nervous system depressant effects. However, the sole active metabolite, normeperidine, is a central nervous system excitatory agent and has the ability to cause seizures, especially in patients with renal failure. Patients with normal renal function rarely manifest seizure activity when given meperidine, but if the drug is used in large doses at frequent dosing intervals, seizures may occur. Reported here is the case of a man with normal renal function who had a tonic-clonic seizure due to meperidine that was administered for the pain of underlying chronic pancreatitis.