BACKGROUND Multiple primary malignancy (MPM) is defined as 2 or more primary malignancies diagnosed in the same patient. Even though MPMs are rare, various associated tumors have been reported in the literature. We report the first case of triple synchronous primary malignancies: gastrointestinal stromal tumor, colon adenocarcinoma, and renal cell carcinoma. CASE REPORT A 63-year-old man presented to our emergency department with a 7-day history of diffuse abdominal pain and constipation. Examination revealed a distended abdomen and diffuse tenderness. Enhanced computed tomography showed a high-grade large bowel obstruction with the transitional zone seen at the splenic flexure, which was suspicious for primary colon cancer, and a hypodense lesion on the left mid-pole of the kidney. An emergency exploratory laparotomy revealed a splenic flexure mass, which was resected, and a left renal mass, which was excised. A stomach mass at the greater curvature was an incidental intraoperative finding; a wedge resection was performed for it. The pathology for each of the masses showed a primary malignancy. CONCLUSIONS Multiple primary cancers are rare and a multidisciplinary team approach is essential for management of these patients, be it preoperative, intraoperative, postoperative, or long-term surveillance.