Colorectal cancer is extremely rare in children. We report a case of a 12-year-old boy who presented with a five-month history of weight loss and anorexia, associated with vomiting episodes, dizziness, fatigue, and dyspnea. On physical examination, a palpable abdominal mass was noticed on the right hypochondrium and flank. An imaging study was performed, which showed a solid mass on the right colon. The patient underwent incisional surgical biopsy, and subsequent histopathologic analysis revealed a colon mucinous adenocarcinoma.