Physical inactivity is a strong predictor of mortality in patients with end-stage renal disease and is associated with poor physical functioning. Patients with end-stage renal disease are inactive even compared to sedentary individuals without kidney disease. We sought to identify patient barriers to physical activity. Adult patients on hemodialysis in the San Francisco Bay Area were recruited and asked to complete a study survey composed of questions about self-reported level of physical functioning, physical activity participation, patient physical activity preference and barriers to physical activity. Univariate and multivariable linear regression analyses were performed to study the association between barriers to physical activity and participation in physical activity. A total of 100 patients participated in the study, the majority of whom were male (73%), with a mean age of 60 ± 15 years. Twenty-seven percent identified themselves as white, 30% black and 21% Hispanic. The majority of participants strongly agreed that a sedentary lifestyle was a health risk (98%) and that increasing exercise was a benefit (98%). However, 92% of participants reported at least one barrier to physical activity. The most commonly reported barriers were fatigue on dialysis days and non-dialysis days (67 and 40%, respectively) and shortness of breath (48%). In multivariate analysis, a greater number of reported barriers was associated with lower levels of physical activity (P < 0.02). Post-dialysis fatigue was not associated with differences in activity level in multivariate analysis. Lack of motivation was associated with less physical activity. Endorsement of too many medical problems and not having enough time on dialysis days were also associated with less activity in adjusted analysis. We have identified a number of barriers to physical activity that can be addressed in studies aimed at increasing levels of physical activity. Inconsistent with nephrologists' reported assumptions, dialysis patients were interested in physical activity.