This study is aimed at applying a previously described PCR-based method to detect B. burgdorferi sensu lato and different Borrelia genospecies in total DNA preparations of serum samples collected from people with different occupational risks for tick bite and with serological evidence of borreliosis. Among the seropositive samples, the PCR for B. burgdorferi confirmed the positivity in 65 percent of the forestry workers and in 60 percent of the subjects living in the same area. None of the seronegative subjects belonging to the control group showed the presence of B. burgdorferi sensu lato DNA. Results on genospecies distribution show that B. afzelii was the predominant species, followed by B. garinii and finally by B. valaisiana.