Lyme borreliosis is an infectious disease with various clinical manifestations, caused by the bacterium Borrelia burgdorferi. Although symptoms of the disease have been described since more than 100 years ago, it was not until 1982 that the causative organism was discovered. In Europe, Lyme borreliosis is the most common tick-borne disease, and in endemic regions, a considerable number of clinical cases can be found. The course of the disease is in stages and involves various organ systems, such as skin, nervous system, heart, and joints. Laboratory diagnosis is considered to be difficult and relies mainly on the determination of antibodies. A vaccine for use in humans is not yet available, but experimental data support the feasibility of a vaccine development.