The Province of Pesaro-Urbino, situated in the Marche Region of central Italy, can be considered to be an area at risk for Lyme disease because of its ecological features. Field data are not yet available although the disease is known to be present in neighbouring areas. During a field study lasting twelve months, ticks were collected from the vegetation, from wild cervids and also from humans who reported a tick bite at the local hospital. All ticks were identified and Ixodes ricinus specimens were tested using three different polymerase chain reaction tests for the detection of Borrelia burgdorferi sensu lato (sl). To identify the genospecies of B. burgdorferi sl, a fragment of the 5S-23S ribosomal rRNA intergenic spacer of the positive samples was amplified and then sequenced. Sequencing of the 5S-23S intergenic spacer led to the identification of two different genospecies, namely: B. burgdorferi sensu stricto and B. lusitaniae, both of which are involved in cases of human infection. Findings on the host-tick relationships and on the genospecies involved in the cycle of borreliosis confirm the suitable conditions for Lyme disease in the study area. The results concur with previous findings reported in the Mediterranean region.