In the framework of EUROCARE, a concerted action between 45 population-based cancer registries, in 17 European countries, survival of patients with primary malignant brain tumours was investigated. Survival analysis was carried out on 16,268 patients diagnosed between 1985 and 1989 and followed-up for at least 5 years. The mean European age-standardised 5-year relative survival was 17% in men and 20% in women, with minimal intercountry variations, except for markedly lower rates in Scotland, Estonia and Poland. The age-specific analysis showed a relatively uniform survival in patients aged more than 65 years at diagnosis, but there were more marked intercountry differences in younger patients. In the 15-44 year age group (25% of the total study population) 5-year relative survival ranged between 55% (Finland and Sweden) and 27% (Poland). Generally, survival decreased with increasing age at diagnosis. The analysis of a temporal trend in survival was carried out on a subset of registries with available data from 1978-1989. Overall, there was an increase in survival over the considered study period, mostly confined to 1-year survival, suggesting that it was mostly related to improved diagnostic techniques. The most important survival increase occurred in the younger patients, both for 1- and 5-year survival, suggesting that younger patients have less biologically aggressive tumours, benefiting from the combined effect of diagnostic accuracy and effective therapies. The most marked survival increase was seen in England and Denmark, countries with low survival rates at the beginning of the study period, whereas in Finland and Germany, where survival was relatively high to begin with, no important temporal trend was seen.