© 2016 Cancer Research UK. Background:Existing literature examining analgesic medication use and epithelial ovarian cancer (EOC) risk has been inconsistent, with the majority of studies reporting an inverse association. Race-specific effects of this relationship have not been adequately addressed.Methods:Utilising data from the largest population-based case-control study of EOC in African Americans, the African American Cancer Epidemiology Study, the relationship between analgesic use (aspirin, non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs), and acetaminophen) and risk of EOC was estimated by multivariate logistic regression. The association of frequency, duration, and indication of analgesic use on EOC risk was also assessed.Results:Aspirin use, overall, was associated with a 44% lower EOC risk (OR=0.56; 95% CI=0.35-0.92) and a 26% lower EOC risk was observed for non-aspirin NSAID use (OR=0.74; 95% CI=0.52-1.05). The inverse association was strongest for women taking aspirin to prevent cardiovascular disease and women taking non-aspirin NSAIDs for arthritis. Significantly decreased EOC risks were observed for low-dose aspirin use, daily aspirin use, aspirin use for <5 years, and occasional non-aspirin NSAID use for a duration of ≥5 years. No association was observed for acetaminophen use.Conclusions:Collectively, these findings support previous evidence that any NSAID use is inversely associated with EOC risk.