In 1996, as part of Kaiser Permanente Southern California's participation in the Medicare End-Stage Renal Disease Managed Care Demonstration Project, a multidisciplinary continuous quality improvement (CQI) committee was formed, which included nephrologists, vascular surgeons, interventional radiologists, care managers, a renal quality-improvement nursing director, and renal program administrators. The goal of this report was to analyze the impact of this CQI program on hemodialysis outcomes within the organization. Kaiser Permanente is a national, integrated, nonprofit, staff model health maintenance organization with 8 million members. The southern California region has 3.1 million members and currently manages the health care of 3,700 hemodialysis patients, 300 peritoneal dialysis patients, and 1,000 kidney transplant patients. Thirty-one vascular surgeons and 29 interventional radiologists provide for their hemodialysis access needs. The Kidney Disease Dialysis Outcomes Quality Initiative (K/DOQI) guidelines were adopted, as well as measures to perform more venous transpositions and less common arteriovenous fistulas (AVFs) before graft placement. The outcomes assessed included incidence and prevalence of AVFs, grafts, and catheters; replacement access with AVFs; and combined AVF and graft thrombosis episodes per patient per year. Primary AVF incidence rates increased from 27% in 1997 to 88% in 2003. AVF prevalence rates increased from 30% in 1997 to 62% in 2003. Replacement access which is an AVF increased from 26% in 1998 to 58% in 2003. Yearly thrombosis episodes/patient decreased from 0.62 in 1998 to 0.34 in 2003. Catheter usage as of 2003 comprised an incidence of 65% and prevalence (> or =90 days) of 13%, which was essentially unchanged from 1999, despite improvements in fistula usage and thrombosis rate. The rate of AVF prevalence can be increased dramatically, exceeding the 40% K/DOQI recommendation, by using the CQI process. Increased prevalence of AVF is associated with a lower yearly incidence of thrombosis episodes/patient. Reducing excessive catheter usage appears to be a more difficult problem.