A 68-year-old woman presented a rare lateral abdominal wall hernia. Three month before admission to Chungbuk National University Hospital, she found a large protruding mass measuring 8 cm in diameter in the midaxillary line just below the costal margin upon heavy coughing. She had no history of abdominal trauma, infection, or operation previously. The mass was easily reduced manually or by position change to left lateral decubitus. CT scan showed a defect of the right transversus abdominis muscle and internal oblique muscle at the right flank with omental herniation. Its location is different from that of spigelian hernia or lumbar hernia. The peritoneal lining of the hernia sac was smooth and there was no evidence of inflammation or adhesion. The hernia was successfully repaired laparoscopically using Parietex composite mesh with an intraperitoneal onlay mesh technique. The patient was discharged uneventfully and did not show any evidence of recurrence at follow-up visits.