OBJECTIVE To determine the impact of a 20-week intradialytic exercise program, consisting of 60 minutes of cumulative duration, low-intensity exercise during the first 2 hours of dialysis, on dialysis efficacy, physical performance, and quality of life in self-care hemodialysis (HD) patients. METHODS One-group repeated measures. METHODS Satellite HD units affiliated with a Canadian teaching hospital. METHODS A convenience sample of 13 self-care HD patients who were stable on dialysis for a minimum of 6 months and were medically screened for significant cardiac, pulmonary, and/or musculoskeletal pathology that would preclude exercise. METHODS A 5-month intradialytic exercise program in which subjects exercised 3 times a week (cycle ergometer, mini-stepper) for 30 minutes in each of the first 2 hours of HD. METHODS Dialysis efficacy (in single-pool model of urea kinetics [spKt/V]) was assessed prior to and at the end of each month of the exercise program. Physical function (6-minute walk test [6MWT]), and quality of life. (Kidney Disease Quality of Life-Short Form [KDQOL]) were determined at baseline and at weeks 10 and 20 of the exercise program. RESULTS SpKt/V increased 11% at the end of the first month of the program (P<.05) and remained elevated for the duration of the program (18%-19%). Distance walked on the 6MWT increased by 14% at both weeks 10 and 20 (P<.05). No changes were noted in KDQOL scores. CONCLUSIONS A low-intensity intradialytic exercise program is a viable adjunctive therapy, which improves HD efficacy and physical function in HD patients.