Large, long-term databases are needed in order to provide information on the safety and efficacy of new agents used in the treatment of rheumatoid arthritis (RA) and psoriatic arthritis (PsA). These databases can provide data which is well beyond what is available from industry-sponsored investigations.The structure, governance, content, context and developmental plan of the CORRONA database is described.The CORRONA database has grown from start up in 2002 to the largest independent database in North America which collects data from both rheumatologists and patients at the time of a clinical encounter. Data are collected as often as every 3 months in RA and every 6 months in PsA. As of the time of this writing, the CORRONA database consists of approximately 9,000 patients with RA and 1,000 with PsA. Data can be used to elucidate toxicities found in frequencies which would be considerably less common than can be uncovered in industry-sponsored investigations. In addition, actual prescribing patterns and responses in clinical practice can be investigated and described.After 3 years of data collection, the CORRONA database is now appropriately able to make significant contributions to our understanding of the safety, efficacy of drugs, as well as demographic, and socioeconomic profiles of patients with RA and PsA. It has evolved from a nascent database to a mature one poised to make significant contributions.