During the past few decades, it has been stated that a paradigm shift has occurred in the assessment and management of patient related drug safety. Some of these changes have resulted in a significant increase in the importance of pharmacoepidemiology and its use in pharmacovigilance. For European member states, the Pharmacovigilance Risk Assessment Committee (PRAC) is responsible for assessing the protocols and results of imposed and non-imposed post-authorization safety studies (PASS). Between 2013 and 2017, the total number of PASS during this 5-years period of the different products, including protocols and results, was 1062. The number of protocols of PASS is increasing over time, except in 2017 where a 25% decrease has been observed. Whereas, PASS results steadily increased over the 5years period. Between 2014 and 2017, about 29% (n=137) of PRAC reviewed protocols were imposed. The number of imposed PASS was almost constant over time with a mean of 34.3±7.6 imposed protocols per year and 3.5±1.74 imposed results per year. The need for the implementation of PASS for pharmacovigilance regulatory activities is increasing. Nevertheless, conducting such studies remains difficult.