Literature review revealed a compelling pre-clinical rationale for statins as chemopreventive agents for prostate cancer (PC). However, epidemiological literature results vary widely. We completed a nested case-control study investigating the impact of statin use on PC diagnosis using data from men aged >=40 years in Saskatchewan between 1990-2010. Drug exposure histories were derived from a population-based prescription drug database. We used conditional logistic regression to model use of statins. 12,745 cases of PC were risk-set matched on age and geographic location to 50,979 controls. 2064 (16.2%) cases and 7956 (15.6%) controls were dispensed one or more statin prescriptions. In multivariable models, ever prescription of statins was not associated with PC diagnosis (OR 0.97; 95% CI 0.90-1.05). Diagnosis of clinically significant PC decreased with statin use (OR 0.84, 95% CI 0.73-0.97). Statin use is not associated with PC risk, but is associated with a decreased risk of clinically significant PC.