A 54-year-old woman with severe pains in the region of the right arcus costalis is presented. This case was a great therapeutic and diagnostic problem during 4 weeks. A borrelia meningoradiculitis was finally diagnosed by detection of specific antibodies in the cerebrospinal fluid. Intravenous benzylpenicillin in combination with epidural morphine hydrochloride resulted in a dramatic relief of the severe pains.