In the United States, 87.3% of the patients with end-stage renal disease (ESRD) requiring dialysis are treated with hemodialysis (HD) and 12.7% with peritoneal dialysis (PD). This represents a greater use of HD than in many other nations. We mailed a survey questionnaire to members of the National Kidney Foundation Council on Dialysis to better understand the attitudes of American nephrologists toward dialysis modality decisions. We received responses from 240 of 507 nephrologists (47.3%). The respondents were heavily involved in clinical dialysis work. Results showed that decisions regarding modality selection were strongly based on patient preference (4.54 on a scale of 1 to 5), quality of life (4.18), morbidity (4.02), and mortality (3.90), whereas the least important factors reported were facility reimbursement (2.09) and physician reimbursement (1.98). When asked about the current use of modalities, hospital-based HD and full-care HD were believed to be overused (2.63 for each on a scale of 1 [vastly overused] to 5 [vastly underused]), whereas home HD (4.29), continuous ambulatory PD (3.71), and cycler PD (3.59) were underused. A hypothetical question about optimal modality distribution to maximize survival or cost-effectiveness showed that HD should constitute 71% or 66% of dialysis (with 11% or 14% in the form of home HD, respectively). PD use would increase between two- and threefold over current practices. Our results suggest that American nephrologists believe home therapies are underused. Because modality distribution is an important determinant of costs and possibly outcomes in patients with ESRD, there is an urgent need for further research in this area.