Müllerianosis is a term used to indicate lesions composed of an admixture of two or three types of müllerian-derivation glands in heterotopic sites. In this report we describe a case of spinal cord müllerianosis which occurred in a 42-year-old woman. The patient had suffered from catamenial lumbago and sciatica of three years duration before undergoing laminectomy of L2-L3 with excision of a polypoid mass that compressed nerve trunks. At histological examination, the lesion was composed of endocervical, endometrial and tubal glands within a smooth muscle nodule. These features were consistent with a diagnosis of müllerianosis. This is a very uncommon form of presentation of müllerianosis that must be correctly identified since patients can benefit from hormonal therapy.