A batch of 259 Ixodes ricinus ticks collected by flagging in woodlands of north-western Poland (Szczecin area) was examined for the presence of Toxoplasma gondii DNA with nested polymerase chain reaction (PCR). Positive isolates were genotyped with the restriction fragment length polymorphism (RFLP) analysis of B1 gene marker. Another batch of 340 I. ricinus ticks from Szczecin area was homogenized and inoculated into mice. Subsequently, the biological material obtained from inoculated mice was also examined with nested PCR for the presence of Toxoplasma gondii DNA and positive isolates were genotyped with RFLP as above. The study revealed that 12.7% of I. ricinus ticks were infected with T. gondii. Prevalence of T. gondii infection was highest in females (27.9%), being significantly greater (p<0.05) than in males (12.3%) and nymphs (5.6%). Most of the positive isolates (78.8%) belonged to type I of T. gondii. Samples from brains and other organs of 60 inoculated mice showed 44 positive results for T. gondii DNA with the dominance of atypical genotype and frequent mixed infections.