Caecal and right sided colonic cancers mostly present with fatigue, weakness and iron deficiency anemia. Such tumours rarely perforate posteriorly and involve the retroperitoneum. We report a case of an old Omani lady who came with insidious sign and symptoms of perforated caecum leading to retroperitoneal collection and necrotizing fasciitis of abdominal wall due to carcinoma of caecum. She underwent surgery but despite active intervention, she died because of septicemic shock.