Both the presence of Anaplasma phagocytophilum in ticks and the seroprevalence of human granulocytic anaplasmosis have been reported in different parts of Europe. There are few reports concerning this problem in Poland. The aim of the study was to assess the prevalence of Anaplasma phagocytophilumin ticks, and to detect antibodies against the HGE agent in serum of forest workers in the region of Mid-Eastern Poland. In our opinion, this should reflect the real probability of infection of people exposed to Ixodes tick bites. Seroactivity against Anaplasma phagocytophilum was detected in 20.6% of personsin the study group. Coexistence of anti-Borrelia burgdorferi was present in 84.6 % of individuals seropositive to A. phagocytophilum. The PCR test identifying Anaplasma phagocytophilum was positive in 13.1% of overall tick samples. The highest prevalence of infection (45.7%) was found in female ticks. Anaplasmal DNA was detected in 4.5% of male ticks and only in 0.9% of nymphs. The results of our study confirmed the existence of A. phagocytophilum in the natural environment of Mid-Eastern Poland. As the risk for infection exists, it should call the attention of public health services to the possibility of an increasing number of patients with this disease.