Objectives: To examine 5-year survival from haematological malignancies in children, adolescents and young adults in Australia and determine if there has been any improvement in survival for the older age groups compared with children (the age-related "survival gap") Design, setting and participants: Population-based study of all Australian children (aged 0-14 years), adolescents (15-19 years) and young adults (20-29 years) diagnosed with acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) between 1982 and 2004, with follow-up to 2006 Main outcome measures: 5-year survival from ALL, AML, HL and NHL analysed for four periods of diagnosis (1982-1989, 1990-1994, 1995-1999 and 2000-2004) Results: During 1982-2004, 13015 people aged <= 29 years were diagnosed with primary leukaemia or lymphoma in Australia For those with ALL, 5-year survival for adolescents improved from 40% (1982-1989) to 711% (2000-2004), the improvement for young adults was smaller (31% to 47%), and both these groups still had lower survival than children, whose 5-year survival improved from 74% to 88% There was a larger narrowing of the gap for AML for cases diagnosed in 2000-2004,5-year survival was similar for young adults (63%), adolescents (74%) and children (69%) For lymphoma cases diagnosed in 2000-2004,5-year survival in all age groups was greater than 95% for HL and greater than 81% for NHL, although children fared better than adolescents and young adults Conclusions: These Australian population-based data confirm an improvement in survival from haematological malignancies across all three age groups, but an age-related survival gap remains for adolescents and young adults compared with children, especially for young adults with ALL Greater participation of adolescents and young adults in clinical trials and more detailed data collection are needed to provide evidence about optimal treatment regimens in these age groups MJA 2010, 193 217-221