OBJECTIVE To investigate the effects of the presence/absence of potassium in the dialysate on total body potassium content in stable hemodialysis patients. METHODS Randomized selection. METHODS Outpatient chronic hemodialysis unit at the James A. Haley VA Hospital in Tampa, Florida. METHODS Six adult hemodialysis patients (mean age 48 +/- 11.61 years, range 32-65 years) participated in this study. They were all males, four African-Americans and two Caucasians. METHODS Subjects in a random order received dialysis using a dialysate containing no potassium for 3 months, followed by a 2 mEq/L of potassium for another 3 months. Total body potassium measurements and routine blood analysis were taken at baseline and after each three month period. All subjects received diet instruction pre and monthly on a 3 g/day potassium dietary restriction. METHODS There were no significant differences in the amount of total body potassium concentration between the two different dialysates containing 0 or 2 mEq/L potassium. Mean values of serum albumin were significantly higher when the subjects were dialyzed on a 0 potassium bath. CONCLUSIONS The use of dialysate containing 0 or 2 mEq/L potassium concentration does not make a significant difference with regard to total body potassium concentration and maybe advantageous for the patients in terms of more freedom in nutritional intake as demonstrated by a significant increase in serum albumin when they were dialyzed on a 0 potassium bath.