Drug safety evaluation is crucial in the understanding of a product’s risk to benefit profile; however, identifying a safety signal in pre-market clinical trials is often difficult if the event is rare and not systematically assessed. Similarily, designing large simple safety trials, product registries, or observational studies is often challenging due to sample size and time restrictions, lack of historical information, and a lack of validated measures or assays for the outcome measure. This session will discuss these challenges along with some recent examples of pre-and post-market safety study designs and analyses.