Cytomegalovirus (CMV) is a viral agent that can cause various clinical signs according to the patient’s immune status. Primary CMV infection is usually asymptomatic in patients with a normal immune system and can lead to a self-limited, mononucleosis-like syndrome. We present a two and a half months old female with CMV mononucleosis, negative direct Coombs test, hemolytic anemia and thrombocytopenia. The patient presented with restlessness and cough and the examination revealed paleness, hepatosplenomegaly, and retarded growth and development. Laboratory tests showed leukocytosis, anemia, thrombocytopenia, and liver function disorder while peripheral smear showed CMV mononucleosis and reticulocytosis. Other results were CMV IgM (+), CMV PCR (+), direct Coombs (-), and haptoglobin level low. No treatment was given. The patient made a full clinical and laboratory recovery with no complications. In conclusion, cytomegalovirus infection should be considered in the differential diagnosis of hemolytic anemia and thrombocytopenia. Supportive care with untreated attitude is adequate for patients with normal immunity

Keywords: Direct Coombs test, Hemolytic anemia, Mononucleosis, Cytomegalovirus, Thrombocytopenia