Attention must be paid to the furcal nerve when analyzing lumbosacral radicular symptoms, especially when neurologic findings are atypical and the responsible level cannot be assessed. An anatomic and clinical study of the furcal nerve showed the following: the furcal nerve was found in all dissections, and it arises at the L4-root level in most dissections (93%); the furcal nerve has its own anterior and posterior root fibers and its own dorsal nerve root ganglion. This proves that the furcal nerve is an independent nerve root. Neurologic symptoms, suggestive of two roots being involved, are frequently due to furcal nerve compression.