The coincidence of a lumbar disk herniation L4-5 and a neurinoma at the L5 nerve root in a 52-year-old male is reported. The clinical course revealed typical signs of a herniated disk, whereas the tumour was accidentally found by myelography initially performed for the suspected prolapse. Both lesions were removed without complications. The clinical and neuroradiologic aspects of this rare condition are discussed, with special regard to the problems of differential diagnosis. A review of the literature is added.