A 10-month-old ram with fever, inappetence and haemorrhagic diathesis had petechiae and ecchymoses at various body sites and was infested by ticks. Haematological examination revealed pancytopenia, while serum biochemistry indicated hepatic dysfunction. Blood smears were negative for Ehrlichia spp. and other haemoparasites. Paired sera revealed infection by Anaplasma phagocytophilum, but testing by polymerase chain reaction was negative. Treatment with oxytetracycline was effective. This is the first reported clinical case of ovine anaplasmosis in Greece caused by A. phagocytophilum.