Ten years after detection of Borrelia burgdorferi as the etiologic agent of Lyme borreliosis and after introduction of serological methods an overview of the disease in children is given and compared with own observations. In view of the wide clinical spectrum and the difficulties in interpreting serological results the early diagnosis of Lyme borreliosis is still problematic at present. On the other hand, in case of late diagnosis therapeutic failure and/or partial recovery may result. Data of 138 children with clinically suspected recent Lyme borreliosis demonstrate that the early diagnosis particularly of neuroborreliosis can only be ameliorated when a careful synopsis of all specific and nonspecific laboratory parameters available is done. Additionally, the results of a prospective randomized study of the treatment of acute neuroborreliosis (penicillin G sodium versus ceftriaxone) and results of liquor patency and half-life of ceftriaxone are presented.