Pseudomyxoma peritonei is very rare, and its exact pathogenesis is unknown. It is characterized by intra-abdominal extracellular gelatinous fluid collections. We report a case of pseudomyxoma peritonei in a 38-year-old Saudi male who presented with right iliac fossa mass and weight loss. He was treated initially as an appendicular mass and computed tomography was helpful in making the diagnosis. He was treated by laparotomy, right hemicolectomy and omentectomy, but no perioperative intraperitoneal chemotherapy was instilled. He received postoperative chemotherapy and remained alive with no recurrence at 18-month follow-up.