Lyme borreliosis (LB) is the most frequent infection transmitted by ticks from the Ixodes genus, both in the United States of America (USA), and in Europe. The objectives of this study were the monitoring of the incidence and clinical manifestations of the disease in Mures County, Romania. Material and method. The study was conducted over a period of two years, January 1st 2010 -December 31st 2011, on a number of 120 consecutive patients. The definite or probable diagnosis of LB was established on the Centers for Disease Control and Prevention (CDC, Atlanta, USA) criteria, and on the European Union Concerted Action on Lyme borreliosis (EUCALB). ELISA and Western-Blot techniques were used for identification of IgM and IgG antiBb from the serum and CSF. Results. There were 44 cases in 2010 and 76 cases in 2011. According to the case definition, 106 cases were confirmed as LB and 14 were probable. LB was more frequently diagnosed in children, young adults and adults, compared to the over 60 years old age group. The incidence of disease was higher in women patients, 68 (56.66%) compared to men - 52 patients (43.33%), with a higher proportion in people coming from an urban setting, 78 patients (65%), compared to people coming from rural settings 42 patients (35%). Clinical manifestations were acute, like erythema migrans (EM) in 64.16% of the patients, neurological in 22.5% of the patients, joint related in 1.66% of the patients and cardiac in 0.83% of the cases. Conclusions. In Mures County we have observed an increased incidence of this disease in 2011 vs. 2010. The predominant clinical manifestations were the acute dermatological and neurological ones.