GASTRO-INTESTINAL STROMAL-TUMOURs (GASTRO-INTESTINAL STROMAL-TUMOURs) are tumours of the gut found mostly in stomach and small intestine. The complications are Gastrointestinal (GI) bleeding, obstruction, pain and rarely perforation. We are reporting an abnormal presentation of GASTRO-INTESTINAL STROMAL-TUMOURS presenting as an acute abdomen pain with Right Iliac Fossa (RIF) mass in 57-year-old male. Contrast Enhanced Computed Tomography (CECT) of abdomen revealed a peripherally enhancing encapsulated abscess in RIF close to the base of caecum and surrounding peritonitis suggesting a caecal perforation. On laparotomy, a perforated ileal GASTRO-INTESTINAL STROMAL-TUMOURS was identified. Pathological examination confirmed the tumour to be a GASTRO-INTESTINAL STROMAL-TUMOUR of spindle cell type, further reiterated by immunohistochemistry. Our case report emphasizes, GASTRO-INTESTINAL STROMAL-TUMOUR are a rare differential diagnosis of RIF mass, and to have high clinical suspicion when a similar case is encountered in an emergency room, keeping in mind the poor outcome caused by delay in appropriate management of the disease.