A case in which an embryonal rhabdomyosarcoma of the cervix and an ovarian Sertoli-Leydig cell tumour of intermediate differentiation occurred in a 13-year-old girl is described. Although initially considered as a chance association, a review of the literature showed the co-occurrence of these two uncommon neoplasms in three previous cases. The reason for this association, which is thought to be more than coincidental, is not known, although an underlying genetic abnormality is a possibility. The ovarian tumour in this case was characterised by the presence of foci of cells with extremely pleomorphic nuclei, which initially raised the possibility of metastatic rhabdomyosarcoma. These were interpreted as foci of bizarre nuclei within the Sertoli-Leydig cell tumour.