OBJECTIVES: Differences in efficacy of different classes of blood pressure lowering drugs (BPLDs) have been observed in elderly primary prevention populations, with beta-blockers (BBs) reported to be less efficacious for primary prevention. In this study, we assessed if these differences remained significant in patients that use statins concurrently. METHODS: We conducted a series of population-based nested case-control studies using administrative data from 104,023 diagnosed hypertensive patients without recent antecedents of diabetes or cardiovascular disease (CVD) in the province of Quebec (Canada) between 2000 and 2004. Follow-up ended either with an outcome event, or at the end of 2009. Individuals with an outcome event (all-cause death, CVD event) were considered cases. Controls were matched according to age, sex, date of cohort entry, and comorbidity index. Conditional logistic regression was used to estimate the odds ratio of the outcome events for patients whose treatment in the week before event date included statins and BBs as compared to patients whose treatment included statins and other BPLD(s). RESULTS: Patients on statins and BBs showed substantially higher risks for cardiovascular death (OR=2.12, 95%CI: 1.81–2.49), all-cause death (OR=1.64, 95%CI: 1.49–1.81), CVD events (OR=1.96, 95%CI: 1.80–2.12) and hospitalization for CVD (OR=1.99, 95%CI: 1.82–2.17) as compared to patients on statins and other BPLDs. Sensitivity analyses suggest that this higher risk is not due to differences in prescription patterns based on perceived disease severity (indication bias).   CONCLUSIONS: In elderly hypertensive patients, the concurrent use of statins and BBs is associated with less effective primary prevention in comparison to the use of statins in combination with other BPLDs. Consequently, the difference observed in the efficacy of different classes of BPLDs in elderly populations in primary prevention remains significant in the subpopulation receiving statins. Further studies should be conducted to confirm this finding.