To determine trends in a number of hemodialysis associated diseases and practices, the Centers for Disease Control and Prevention, in collaboration with the Health Care Financing Administration, completed a mail survey of chronic hemodialysis centers in the United States in 1992. Of 2,321 centers surveyed, 2,170 (93%) representing 170,028 patients and 43,535 staff members responded. In 1992, 2,049 (94%) centers used bicarbonate dialysate as the primary method of dialysis, 765 (35)% used high flux dialysis, and 1,569 (72%) reused dialyzers, continuing the trends toward increased use of these methods. Central (subclavian or jugular) venous catheters were used in ≥1 patient as permanent vascular access for hemodialysis at 69% of dialysis centers. Hepatitis B surface antigen was present at low frequency in patients (incidence = 0.1%, prevalence = 1.2%) and staff members (incidence = 0.03%, prevalence = 0.3%). Among centers that had ≥1 hepatitis B surface antigen positive patient, the incidence of hepatitis B virus infection was lower in those centers that used a separate room for dialysis of patients positive for hepatitis B surface antigen. From 1991 to 1992, reported hepatitis B vaccine coverage increased from 17% to 24% among patients and from 56% to 69% among staff members;in absolute terms, these were the largest single year increases since introduction of hepatitis B vaccine. The prevalence of antibody to hepatitis C virus was 8.1% among patients and 1.6% among staff members. Pyrogenic reactions in the absence of septicemia were reported by 19% of centers and associated with use of high flux dialysis. New dialyzer syndrome was reported by 24% of centers, most frequently by centers using regenerated cellulose or cuprophan membranes. Human immunodeficiency virus was known to be present in 1.5% of patients; 34% of centers reported providing hemodialysis to one or more patients infected with HIV.ASAIO Journal1994; 40:1020-1031.