Patient registries have been gaining increasing attention in recent years as health care providers, payers and regulators are requiring data that more accurately reflect clinical practice. However while the number of registry based studies is undoubtedly increasing, little is known about the range and characteristics of registries supporting these studies. A review of the published literature was performed to identify recently reported studies based on patient registries. The search which covered the period January 2008 to April 2009 retrieved 278 evaluable articles reporting data from disease (55%), exposure (42%) and pregnancy (3%) registries. The majority of studies based on disease registries were focused on cardiovascular disease (49%), oncology (12%), renal disease (10%), haematology (8%) and gastrointestinal disease (7%). Data from exposure registries reported on patients who had received a pharmaceutical product (47%), device (28%), undergone a surgical procedure (22%) or other intervention including radiotherapy (3%). Several registries have provided data able to support multiple publications for example the REACH registry. The most frequently performed assessments were evaluation of benefit (46%), risk (34%), treatment practice (31%) and burden of disease (23%). Local or nationally representative patient registries accounted for 83% of the total reviewed. This might be expected given that data is most frequently required in the context of national health care systems by different stakeholders.  However, one new insight this study provides is the use of studies based on an international registry (17%) where design, implementation and management provide much bigger challenges. Further analysis is underway. This research has confirmed that patient registries are being used to provide evidence to inform health care decision making, improve disease management and advance knowledge on the benefits, risks and cost effectiveness of different interventions in clinical practice.