Background-: A recent meta-analysis of randomized trials suggested that use of angiotensin receptor blockers (ARBs) may be associated with a modestly increased risk of incident cancer, particularly lung cancer. Methods and Results-: We linked individual-level data from Danish registries on filled drug prescriptions, diagnostic information, and covariates. In a nationwide cohort of new users of ARBs and angiotensin-converting enzyme inhibitors ≥35 years of age during 1998 to 2006, we compared incidence rates of all cancer, cancer subgroups by anatomic site, and cancer mortality. Among 107 466 ARB users, 3954 cases of cancer were detected during 312 753 person-years of follow-up compared with 6214 cases during 435 207 person-years of follow-up in 209 692 angiotensin-converting enzyme inhibitor users (adjusted rate ratio, 0.99; 95% confidence interval, 0.95 to 1.03). Cancer risk did not increase with increasing duration of ARB exposure (increase in rate ratio per year, 0.99; 95% confidence interval, 0.99 to 1.00,) and was similar across individual ARBs. In subgroup analyses, there was a significant association between ARB use and cancer of male genital organs (rate ratio, 1.15; 95% confidence interval, 1.02 to 1.28), but no significantly increased risk of any of the other 15 cancer subgroups, including lung cancer (rate ratio, 0.92; 95% confidence interval, 0.82 to 1.02). For cancer mortality, the rate ratio was 0.77 (95% confidence interval, 0.72 to 0.82). Conclusions-: In this large nationwide cohort, use of ARBs was not significantly associated with increased risk of incident cancer overall or of lung cancer.