Borrelia miyamotoi is an emerging tick-borne pathogen phylogenetically belonging to spirochaetes causing relapsing fever. It is primarily transmitted by ticks from the Ixodes ricinus complex, similarly to borreliae causing Lyme borreliosis. Small rodents can serve as reservoir hosts. It is widespread in mild climate areas of the northern hemisphere, with constant low prevalence in ticks, in the range of units of percent. To date more than 200 human cases have been described including five cases of meningoencephalitis in immunocompromised patients. Clinical features of illness are non-specific, characterized by fever, fatigue, chills, headaches, muscles and joint pains. It can be treated with antibiotics. The diagnostic approach includes mainly PCR and serological methods. This review summarizes current knowledge on B. miyamotoi with an emphasis on taxonomy, ecology of vectors and reservoir hosts, geographical distribution, diagnosis and treatment of the disease. The review also highlights the need for an accurate determination of the etiology of the disease and its differentiation from Lyme borreliosis and human granulocytic anaplasmosis.