Introduction: Lyme borreliosis/Lyme disease is caused by Borrelia burgdorferi and is one of the most common vector-borne diseases transmitted by ticks. Material and Methods:A total of 136 Ixodes ricinusticks, collected in the Ternopil (Ukraine) region, including 126 adults (70 females and 56 males), and 10 nymphs were examined. The identification of the species and their developmental form was based on morphological characteristics. Results:PCR with B5S-Bor and 23S-Bor primers resulted in Borrelia burgdorferisensu latoDNA amplification among six ticks (4.4%). The detailed analysis based on the DNA sequencing showed the presence of DNA of Borrelia afzeliiin four samples; the remaining two representedBorrelia burgdorferisensu latocomplex, although their genospecies were not determined. The research confirmed the dominance of Borrelia afzeliigenospecies in the ticks from Ukraine. Conclusion:It seems reasonable to undertake similar research in ticks from other regions of Ukraine. Knowledge in this field can be useful for public health and planning the prevention of tick-borne diseases