Intraparietal inguinal hernias are a rare variant of inguinal hernia in which the hernia sac lies between the layers of the abdominal muscles. Intraparietal inguinal hernias mimic Spigelian hernias clinically; the diagnosis presents superior difficulties than its treatment. We report a case of a giant intraparietal hernia misdiagnosed as a Spigelian hernia clinically. The patient was 83 years old woman presented with complain of a large swelling over right abdomen for around 25 years. The patient had a huge mass of 25 x 30 cm occupying right flank, right lumbar region extending up to the umbilicus and inguinal region, partially reducible with gurgling sounds. Surgery started with transversal incision over the mass, it was found to be an interstitial variety of intraparietal inguinal hernia with a long viable segment of the small bowel with their mesentery as content of the sac. Hernioplasty with a polypropylene mesh was achieved satisfactorily. The patient was discharged on third postoperative day without complications. It is challenging to diagnose intraparietal hernias preoperatively; intraoperative findings defined its definitive diagnosis and its surgical technique.