A case of 25 years old woman, living in an endemic area for Lyme borreliosis was examined. In 29 th week of pregnancy thrombocytopenia, fever and fatigue were observed, in the last 7 weeks erythema migrans was present. The woman was not treated by that time. The infant presented thrombocytopenia in the first few weeks of life. 3 months after delivery erythema migrans disseminata was observed, by that time Lyme borreliosis and HGE were serologically confirmed. It was not confirmed that the infection was transferred to the infant, but it is possible that thrombocytopenia was caused by the infection with A. phagocytophila.