Cytomegalovirus (CMV) colitis is a serious and potentially fatal complication in patients living with human immunodeficiency virus (HIV), particularly those with severe immunosuppression. CMV, a virus belonging to the Herpesviridae family, takes advantage of immunosuppression to reactivate, leading to various clinical manifestations, including colitis. We report the clinical case of an HIV-positive patient with CMV colitis confirmed by colonic biopsy. This article explores the epidemiological, pathophysiological, clinical, diagnostic and therapeutic aspects of CMV colitis in HIV-positive patients, based on bibliographical references.