Cytomegalovirus (CMV) retinitis is one of the rare but debilitating presentations of the CMV infection in children with leukemia. Herein, we report a 12-year-old boy with acute myeloid leukemia complicated by rapid progressive visual loss during relapse of leukemia. The definite diagnosis of CMV retinitis was made after vitreous aspiration. Despite prompt treatment and ophthalmologic intervention, he died because of AML relapse. Viral infections, especially cytomegalovirus infection, may present with vague clinical pictures during any time of chemotherapy, which may not be easily distinguishable from bacterial or fungal retinitis and also chemotherapy-induced retinopathies. Clinician should consider CMV retinitis in seropositive patients especially those without detectable viremia.