BACKGROUND: The future burden of cancer in England is predicted to increase by 33% by 2020. Those planning health services are often interested in predictions at a local level. This study aimed to estimate the future burden of cancer in London and compare this with estimates for England. METHODS: Predictions for London were based on cancer registration data (1985-2003) and population projections up until 2024. The number of future cases and age-standardized incidence rates (ASRs) were projected using an age-period-cohort model developed for the analysis of cancer trends and projections in the Nordic countries. Estimates for England were taken from an earlier publication. RESULTS: In London, ASRs for all cancers (excluding non-melanoma skin cancer) decreased for both sexes, whereas in England, ASRs decreased in males and increased slightly in females. In London, the number of cases for both sexes is predicted to increase from approximately 27 000 in 2002 to approximately 28 500 in 2022, an increase of 5%. In England, a greater increase is predicted, from approximately 224 000 in 2001 to approximately 299 000 in 2020, an increase of 33%. CONCLUSIONS: Projections of the future burden of cancer are particularly sensitive to demographic population trends. They are likely to be different for cities compared with rural areas or entire countries.