The international Dialysis Outcomes and Practice Patterns Study (DOPPS) is well suited to evaluate levels of deviation from emerging and established guidelines to clinical practice of hemodialysis, over time and by country. The DOPPS can also evaluate whether the target levels that are chosen in the guidelines are in agreement with outcomes such as elevated risk for mortality, hospitalization, and vascular access failure. At a special DOPPS symposium during the 2004 congress of the American Society of Nephrology, the authors presented such findings; key points from that symposium are presented in this article, focusing on vascular access, mineral metabolism, dialysis dose, and anemia management. Although an observational study cannot prove causality, DOPPS suggests large opportunities to improve care and outcomes of dialysis patients. The international perspective of DOPPS assists in the new efforts for international guidelines. Some encouraging trends in recent years are documented in these areas.