Colorectal carcinomas are extremely rare in childhood and adolescence; however, the colon is the most common site of a gastrointestinal carcinoma. Mucin secreting adenocarcinomas with signet ring formation is the most common type of colon cancer identified in children. An 11-year-old boy had abdominal pain and weight loss for three months, back pain and left thigh pain for two months, and hematochezia for four days. Colonoscopy showed an annular mass in the sigmoid colon and the histopathology revealed a signet ring cell carcinoma. A metastatic signet ring cell carcinoma was suspected from the findings of the bone scan, and confirmed later by a left scalp mass incisional biopsy and a bone marrow biopsy. We report a case of a metastatic signet ring cell carcinoma of the colon in a child.