A 15-year-old boy with systemic lupus erythematosus, who on a follow up visit complained of recurrent episodes of fever, easy fatiguability, and seizures. Investigations revealed lymphocytosis (95%), anemia, and a positive PCR for cytomegalovirus (CMV). Electron microscopy of the lymphocytes revealed intranuclear inclusion bodies supporting the diagnosis of CMV infection. The child was treated with ganciclovir and discharged. At discharge the child was afebrile. However, lymphocytosis persisted even after 9 months of discharge. Repeated screening for possible lymphoreticular malignancy was negative. It is likely that lymphocytosis in this child was due to persistence of CMV infection in host cells leading to continued provocation of the host immune system.