The DOPPS is a prospective cohort study of hemodialysis practices based on the collection of observational longitudinal data for a random sample of patients from a representative and random sample of units in 12 countries (Australia, Belgium, Canada, France, Germany, Japan, Italy, New Zealand, Spain, Sweden, the United Kingdom, and the United States). Since 1996, data collection has yielded detailed information on more than 38,000 patients in over 900 dialysis facilities, and generated over 100 peer-reviewed publications. The study seeks to determine which dialysis practices are associated with the best patient outcomes; its primary goals are improving patient longevity and quality of life. With over 100 peer-reviewed publications, the DOPPS continues to provide findings that are relevant for patients and practicing clinicians. The DOPPS is supported by research grants from Amgen (since 1996), Kyowa Hakko Kirin (since 1999, in Japan), Genzyme (since 2009), Abbott (since 2009), and Baxter (since 2011) without restrictions on publications.