The German Childhood Cancer Registry (GCCR) was established in 1980. From 1980 to 1997 4,447 CNS tumours in children below 15 years of age have been reported to the registry. From 1988 to 1997 the average annual incidence was 2.5/100,000 children. This corresponds to 19.2% of the registered diseases. Compared with incidence rates reported from other developed countries one can estimate that there is about 25% underreporting of CNS tumours in the GCCR. This is in contrast to the relatively complete ascertainment of other childhood malignancies (above 95%). Based on 3012 incident cases from 1988 to 1997 the Kaplan-Meier-estimate of 5-year-survival probability is 65% for all CNS tumours and 54% for PNETs and gliomas. An active long-term-follow-up shows that 30% of 142 children with secondary neoplasms following primary lymphoid leukaemias developed a CNS tumour. Following any primary childhood malignancies 45 CNS tumours were recorded, amongst these were one third leukaemias. The paper reports first results from a population based case control study which included 466 children with CNS tumours and 2,458 healthy controls. These indicate an increased risk for children with low birth weight and for children whose mothers smoked during pregnancy. Additional data can be found in the Internet (http:¿info.imsd.uni-mainz.de/K_Krebsregister).