This study analyses survival in 40,392 children (age 0-14 years) and 30,187 adolescents/young adults (age 15-24 years) diagnosed with cancer between 1995 and 2002. The cases were from 83 European population-based cancer registries in 23 countries participating in EUROCARE-4. Five-year survival in countries and in regional groupings of countries was compared for all cancers combined and for major cancers. Survival for 15 rare cancers in children was also analysed. Five-year survival for all cancers combined was 81% in children and 87% in adolescents/young adults. Between-country survival differences narrowed for both children and adolescents/young adults. Relative risk of death reduced significantly, by 8% in children and by 13% in adolescents/young adults, from 1995-1999 to 2000-2002. Survival improved significantly over time for acute lymphoid leukaemia and primitive neuroectodermal tumours in children and for non-Hodgkin lymphoma in adolescents/young adults. Cancer survival in patients <25 years is poorly documented in Eastern European countries. Complete cancer registration should be a priority for these countries as an essential part of a policy for effective cancer control in Europe.