From a total of 81 patients on maintenance hemodialysis who underwent coronary angiography, 8 patients fulfilled the criteria: significant coronary artery disease, hematocrit < 27%, reproducible (ECG) positive treadmill test, no disturbance of repolarization in ECG at rest. Exercise stress testing was performed at a hematocrit of 25+/-2% and following erythropoietin therapy at a hematocrit of 34+/-0.5%. Symptom-limited exercise performance increased in all patients (1.10+/-0.3 W/kg b.w. vs. 1.44+/-0.31 W/kg b.w., p < 0.01) as well as exercise duration (489 vs. 362 s, p+/-0.01). ST segment depression during maximal exercise was reduced from a mean of 2.1 to 0.4 mm (p < 0.01). It is concluded that amelioration of renal anemia by erythropoietin in dialysis patients with significant coronary artery disease reduces exercise-induced myocardial ischemia.