Lyme borreliosis is an infectious disease, caused by the spirochaete Borrelia burgdorferi and transmitted by ticks, in our regions by the tick Ixodes ricinus. The disease mainly affects skin, nervous system, joints and heart. Lyme borreliosis develops in three stages, and the various clinical manifestations may assigned to the respective stages. As far as skin is concerned, in stage I typically appears erythema chronicum migrans, very often accompanied by flu-like symptoms; in stage III, months to years after the manifestations of the early phase, acrodermatitis chronica atrophicans, may be encountered. Among the neurological manifestations, in stage II, meningoradiculoneuritis (Bannwarth's syndrome) develops as the most frequent disease, characterized by pheripheral paresis at the lower extremities and bilateral facial nerve palsy. Lyme arthritis mainly affects the knee. To assure the diagnosis of Lyme borreliosis, a number of serological tests is performed as the direct detection of the causative agent is rather difficult and time consuming. Possibly, the use of the polymerase chain reaction to detect B. burgdorferi DNA may improve the diagnostic tools.