We experienced a case of paroxysmal supraventricular tarchycardia (PSVT) in a 31-year-old pregnant woman undergoing elective cesarean section under spinal anesthesia. About 15 minutes after delivery of the baby, PSVT suddenly developed. PSVT was difficult to control with a number of medications including esmolol, adenosine and verapamil. Normal sinus rhythm was finally restored after repeated trials of biphasic cardioversion. The patient fully recovered and was discharged without any complication 5 days later.