Results from clinical trials and clinical practice have shown statins to be generally well tolerated with a low frequency of clinically relevant side effects. Nevertheless, there are rare occasions when adverse events (AEs), sometimes serious, may occur. Rosuvastatin is the newest statin to be approved in the USA and many other countries. As part of the continued assessment of the benefit-risk profile of rosuvastatin, AstraZeneca has developed a progressive, comprehensive pharmacoepidentiology programme to complement safety data obtained from randomised clinical trials and spontaneous reporting systems, which have demonstrated that rosuvastatin has a safety profile in line with comparator statins. This programme comprises nine studies conducted in recognised centres of excellence assessing over 50000 patients treated with rosuvastatin. It consists of three components: patient characteristics studies (four studies), safety evaluation studies (four studies); and review of data generated from the Prescription-Event Monitoring (PEM) study, designed and run by an independent third party. Patient characteristics studies are designed to describe the characteristics and drug utilisation patterns of new users of rosuvastatin compared with new users of other statins in automated databases. Safety evaluation studies will examine the rates of specific AEs in different cohorts of statin users and determine risk factors for these events using data recorded prospectively in automated databases with case adjudication via medical record review. The independent PEM study will monitor any significant events recorded by general practitioners since starting rosuvastatin treatment. This article is an overview of the rationale and methodology of the rosuvastatin pharmacoepiderniology programme.