Presented is a review of ehrlichioses, their causative agents, present diagnostic possibilities, clinical manifestations and epidemiological characteristics.Of four recognized human ehrlichioses one can encounter on the territory of the Czech Republic autochthonous infections caused by the species Anaplasma phagocytophilum. This disease should be taken into account in differential diagnosis of cases of febrile illness anamnestically corresponding with localities and season of tick occurrence.

        Key words: ehrlichiosis - laboratory diagnosis - clinical manifestations - prevention - ticks.