Babesiosis is a malaria-like illness transmitted by the tick Ixodes dammini. The disease is endemic to the Northeast coastal region and parts of the Midwest. Symptoms-which include fever, anemia, elevated liver function tests, and hemoglobinuria-may be especially severe in asplenic or immunocompromised patients. In rare cases, infection with Babesia may be associated with marked pancytopenia. Bone marrow biopsy may reveal hemophagocytosis and marrow histiocytosis. We report a severe case of babesiosis and hemophagocytic syndrome in an asplenic renal transplant patient.