Renal primary neuroectodermal tumours (PNET) are exceptional and belong to the vast group of peripheral malignant primary neuroectodermal tumours (MPNT), the best known forms of which are Ewing's sarcoma of bone and Askin's thoracopulmonary tumour. In the light of a case, the authors discuss the clinical features, course, treatment and pathological characteristics, particularly the value of immunohistochemistry and cytogenetics, which demonstrate a specific chromosomal abnormality, the t (11;22) (q24;q12) translocation.