Withholding and withdrawing dialysis are subjects of major concern to nephrologists, because both result in a significant number of end-stage renal disease (ESRD) patient deaths. The medical literature on withholding dialysis is extremely limited, and that on withdrawing dialysis consists mainly of retrospective studies from the 1980s. The present study was conducted to identify ways to improve dialysis decision making by providing a current understanding of how decisions to withhold or withdraw dialysis are being made and by examining whether some patients who might benefit from dialysis are not being referred. In 1995, 22 of 27 (82%) nephrologists practicing in West Virginia agreed to participate in a year-long prospective study in which they completed forms on each patient from whom they withheld or withdrew dialysis. Seventy-six of a random sample of 214 (36%) primary care physicians returned questionnaires describing their practice experience in 1995 with patients with advanced chronic renal failure. The nephrologists withdrew dialysis from 60 of 822 (7%) patients. Academic nephrologists who had received education in the ethics and law of stopping dialysis withdrew it from a greater percentage of patients than those in private practice (12% v 6%; P = 0.009). Patients who were withdrawn more often resided in nursing homes (37% v 2%; P < 0.0001). Twenty-one patients (37%) lacked decision-making capacity at the time the decision was made to withdraw dialysis. Advance directives were available for 13 of the 21 (62%) patients: eight of the 10 treated by academic nephrologists and five of the 11 treated by private practice nephrologists. Academic nephrologists found advance directives to be helpful in decision making to withdraw dialysis of incapacitated patients more often than nephrologists in private practice (70% v 9%; P = 0.004). Nephrologists withheld dialysis from 25 of 357 (7%) ESRD patients compared with 42 of 193 (22%) withheld by primary care physicians (P < 0.001). In deciding not to refer a patient for a dialysis evaluation, 25% of primary care physicians did not consult a nephrologist; 60% cited age as a reason not to refer. These findings suggest that dialysis decision making might be improved by educating nephrologists about the ethics and law of withdrawing dialysis and about how to implement successfully advance care planning so that advance directives will be present and helpful when decisions need to be made for incapacitated dialysis patients. Education of primary care physicians about when to refer patients with chronic renal failure for a dialysis evaluation might also result in more referrals for patients who will benefit from dialysis.