BACKGROUND An increase in the incidence of cancer among elderly people assigned to pravastatin therapy has been reported in a randomized controlled trial; however, this finding has been attributed to chance. Our aim was to assess the effect of pravastatin therapy on cancer risk and to examine whether the effect varies according to age by performing a detailed meta-analysis and meta-regression analysis of randomized controlled trials. METHODS We performed a comprehensive literature search for relevant studies published before February 2006. Before analysis, the selected studies were evaluated for publication bias and heterogeneity. Pooled relative risk estimates with 95% confidence intervals (CIs) were calculated using fixed-and random-effects models. Meta-regression analysis was performed to examine the impact of age on the study estimates of the relative risk of cancer due to pravastatin therapy. RESULTS Twelve trials that investigated the use of pravastatin therapy for cardiovascular outcomes were included in the analysis (n = 42 902). Although the overall association between pravastatin use and cancer was not statistically significant in the fixed-effects (risk ratio [RR] 1.06, 95% CI 0.99 - 1.13) or random-effects model (RR 1.06, 95% CI 0.97 - 1.14), the meta-regression analysis showed that the age of study participants significantly modified the effect of pravastatin therapy on cancer risk (p = 0.006). Specifically, this analysis showed that pravastatin therapy was associated with an increasing risk of cancer as age increased. This finding was remarkably robust in the sensitivity analysis. INTERPRETATION Our findings suggest an association between pravastatin therapy and cancer in elderly patients. However, given the importance of this potential association, further verification is warranted.