This study reports the diagnostic activity for the serological diagnosis of Lyme Disease (LD) in the patients of Abruzzo, a central region of Italy. During the period from August 1994 to July 1999, serological examinations for anti-Borrelia burgdorferi antibodies were performed on 1089 samples from 769 patients with symptomatology consistent with LD. Using an immunoenzymatic technique which was confirmed with Western Blot, 29 patients were diagnosed positive. Twenty-five of these patients contracted the disease in Abruzzo, two during a trip to the USA, one was from Molise and one from Marche. Overall the patients were young, 64% were women and residents of costal areas who frequently engaged in naturalistic activities. The most common symptoms were articular and one patient presented Bannwarth Syndrome. The various antibiotic therapies used gave good results in most cases. These are the first cases reported in literature for this region and for Molise. We believe that LD is underestimated, especially due to the favorable climatic and environmental conditions present in this region. Therefore, we suggest an intensification of clinical and epidemiological controls.