Cytomegalovirus (CMV) infection is often seen in immunocompromised patients. Rarely, immunocompetent patients may present with CMV as a self-limiting, flu-like illness, though a few cases of significant organ-specific complications have been reported in these patients. We report a case in which a previously healthy man presented with hematochezia and an obstructing rectal mass thought to be rectal adenocarcinoma. Biopsy was positive for CMV, which was treated with full resolution of rectal mass confirmed with colonoscopy and barium contrast enema. This is the first reported case of CMV colitis mimicking rectal adenocarcinoma in an immunocompetent patient.