A total of 1,367 Ixodes ricinus ticks collected from 5 districts of the Lublin region (eastern Poland) were examined for the presence of Babesia microti DNA by PCR and nested-PCR. As many as 74 ticks (5.4%) were found to be infected with Babesia microti. The infection rate varied significantly with stage/sex of ticks (chi²=16.48543, df=2, p<0.000264). The infection rates in females and males amounted to 6.4 % and 8.8% respectively and were significantly higher (p=0.006 and p=0.0001 respectively) compared to minimum infection rate in nymphs that was equal to 2.8%. The prevalence of infection showed also a significant variability depending on geographic location within the Lublin region (chi² =18.62812, df=4, p<0.000932). The highest rates of infection with Babesia microti were noted in ticks collected from the areas of Puławy district situated in the northern part of region and the suburban Lublin district situated in the central part of the region (8.0% and 7.3% respectively). Mediocre infection rates (respectively 3.4% and 3.3%) were found in ticks from the Parczew and Włodawa districts situated in eastern part of the region and covered with humid lakeland forests. The lowest infection rate (0.5%) was noted in ticks from the Zamość district situated in southern part of the region. In conclusion, the infection rate of Ixodes ricinus ticks with Babesia microti found in this study is higher compared to the majority of data reported by Polish and other European authors, and indicates a potential risk of human infection during occupational or recreational exposure to tick bite.