The paper summarizes state of art knowledge on tick-borne diseases epidemiology in Poland. The most prevalent diseases are Lyme borreliosis (LB) and tick-borne encephalitis (TBE). Although there is growing number of data published on anaplasmosis and babesiosis prevalence in ticks and humans, there is no national data on these diseases and their epidemiological features remain unclear. All tick-borne agents have a common vector tick--the sheep tick Ixodes ricinus. LB and TBE are mandatory reportable diseases. In 2005 case definitions were implemented in Poland to allow a better comparability of data within the country and with other European countries. LB is widespread in Poland. Studies of prevalence of infected ticks indicate that from 6 to 15% of I. ricinus ticks in different sites are infected with the spirochete. Data from seroepidemiologic studies and from routine surveillance (started in 1996) confirm that the disease is widespread in Poland, and its incidence is increasing. It has increased from 2.31 per 100,000 in 1999 to 11.55 in 2005. One reason of this increase is the improvement in diagnosis of the disease. There is a need to promote personal protection during outdoor activities and knowledge on LB symptoms, especially among populations at risk--forestry workers, farmers. TBE incidence is limited to two main foci--one in the Northeast of Poland bordering Baltic states endemic region, and the second on the South of Poland, neighbouring the Czech and Slovak republics. Seroepidemiologic data, supported by surveillance data, indicate that there are areas of particularly high TBEV activity. The mostly affected occupational groups are: unemployed, retired, students, and farmers. This is a reason to promote personal protection and prophylactic vaccination of both inhabitants of endemic regions and tourists visiting endemic regions.