We report the first case known to us of a synchronous isolated splenic metastasis from colon carcinoma in a 52-year-old woman operated on splenectomy, left colectomy, and ileal resection. The patient died of diffuse carcinomatosis 1 year after the operation. Splenectomy for isolated splenic metastasis from colon carcinoma is justified, and serum tumor markers are useful to detect metastases early during the follow-up, as in our report.