The importance of pharmacovigilance - the ongoing assessment of the safety of a marketed medicine - has been increasingly appreciated in recent years, owing in part to high-profile safety issues with widely used drugs. In response, strategies to improve the collection, integration and analysis of data related to post-marketing drug safety are being initiated or enhanced. In this article, we summarize the key tools that are available for pharmacovigilance, discuss which might be the most appropriate to use in different situations and consider the future directions of the field.