Three pediatric cases of tick-borne meningoradiculitis are presented. This disease is characterized by a distinct sequence of symptoms: erythema chronicum migrans, localized pain, and eventually radicular asymmetric neurologic involvement (in particular facial palsy) associated with findings of aseptic meningitis. On the basis of specific serologic data in these three patients, it is suggested that the etiology of tick-borne meningoradiculitis is also spirochetal , as recently shown for the tick-associated Lyme disease. Analogue positive spirochetal antibody titers were found in additional patients with erythema chronicum migrans and in a child with B afverstedt cutaneous lymphadenosis (see addendum). 20% of tick specimens collected in the area of Lucerne (Ixodes ricinus) were infected by these spirochetes.