Objective: To measure recent changes in prostate-cancer mortality across 24 developed countries. Methods: Mortality data for men aged 50–79 years were obtained from the World Health Organisation mortality database and we assessed trends in age-standardised mortality rates using joinpoint regression models. Results: Significant reductions in prostate-cancer mortality were observed in United Kingdom, United States, Austria, Canada, Italy, France, Germany, Australia and Spain, and downward trends were also observable in the Netherlands, Ireland and Sweden. Conclusions: Mortality declines for prostate cancer are now evident in 12 out of the 24 developed countries considered in this analysis. Increases in PSA screening and better treatment of early-stage disease, possibly acting in combination, remain plausible hypotheses.