A pulmonary edema is not a rare complication in patients with chronic renal failure. Arterial hypertension and fluid overload play a pathogenetically important role. The diagnosis of an unilateral pulmonary edema is often difficult. The following arguments favour the diagnosis: rapid clinical amelioration and disappearance of the alveolar opacities after diuretic treatment alone within 24-72 hours. We describe the case of a 37-year-old patient on dialysis treatment who showed a pulmonary edema of the right lung, predominantly in the upper lobe. This edema was due to fluid overload and mitral insufficiency. After diuretic treatment alone the patient rapidly recovered and the lung infiltrates on the chest X-ray disappeared within a few days.