Lyme borreliosis (LB) is the most common vector-transmitted infectious disease (i.e. disease transmitted by vectors) in Slovenia. From 3,000 to over 6,000 patients with LB were registred from 2005 to 2014 in Slovenia. Since the introduction of statutory registration of LB, incidence rate is increasing and is one of the highest in comparison with other EU countries or United States. The increase reflects better recognition of the disease, awareness of the general population about symptoms and signs consistent with LB and other biotic and abiotic factors whose impact is more difficult to assess. We assume that the lifestyle i.e. living or working in environment where there is a possibility of infection, is equally if not more important than the density of ticks and environmental factors, which will should be studied in near future. Over the past decade climate change (the increase in the average air temperature) might had an impact on increase in incidence rates of LB.