The extent to which hemodialysis patients rely on nephrologists for primary medical care is unknown. The authors surveyed 74 in-center hemodialysis patients to obtain demographic data and information about primary medical care and subspecialty referrals and follow-up. Health care maintenance was also assessed. All patients were dialyzed in a free-standing university affiliated dialysis unit. The mean age of the patients was 55 +/- 17 years; most were women (43/74) and on hemodialysis more than 3 years (48/74). Most of the patients did not have a family physician and relied on the nephrologist for health maintenance care (80%) and the treatment of minor acute illnesses (91%). The most common non-renal chronic illnesses were gastrointestinal disease (32%), heart disease (26%), and diabetes (26%). Although referrals to subspecialists occurred in 55% of patients during the preceding year, nephrologists usually provided ongoing management care (gastrointestinal disease 21/24, heart disease 10/19, diabetes 12/19). Over half the women had a Papanicolaou's test within 3 years and 72% had a routine mammogram that, in most cases, had been ordered by the nurse practitioner or nephrologist. Because nephrologists provide primary medical care to the majority of dialysis patients, preventive health care protocols, such as mammography and cancer screening, should be incorporated into the nephrology practice in chronic dialysis units.