In a prospective, randomised, double blind controlled trial the adverse reactions, food consumption, changes in blood chemistry including acid-base balance, and anthropometry were studied during two consecutive dialysis periods of 3 months, using either acetate- or bicarbonate-based dialysis fluids. Sixteen chronic, stable patients were included. The dialysis fluid sodium content was fixed at 140 mmol/l during all treatments. Patient complaints and adverse reactions were identical using the two dialysis fluids. No differences were observed regarding blood chemistry except for a less pronounced metabolic acidosis present during bicarbonate dialysis compared to acetate dialysis. A slight but insignificant increment in food consumption and nutritional status was noticed during bicarbonate dialysis. In conclusion, the use of a bicarbonate-based haemodialysis fluid offered no significant advantages compared to an acetate-based one in the haemodialysis of chronic, stable patients.