The authors present 34 medulloblastoma/primitive neuroectodermal tumours of the posterior fossa in children operated during the last ten years (1979-1989). Total removal of tumours has been performed in 13, and maximal-subtotal resection in 19 patients. Only four tumours were classified as small (group T1-T2). Partial reduction and biopsy were possible in four cases. The average period from surgery to the beginning of radio-oncologic treatment was 31 days. Radio- and chemotherapy were applied according to international standards. Permanent cerebrospinal fluid derivation preceded surgery in 9 patients (VA shunt in 6 and VP in 3) and after surgery of the posterior fossa in four children. Early postsurgical mortality rate, related to the first five years of this study, was 5.6%. Seven children (20.6%) survived from five to ten years after operation. The authors are advocating for standardization of diagnostical and surgical procedures, and for unification of postoperative control with intention to obtain longer duration of survival of these seriously sick children.