The aim of this study was to evaluate the prevalence of primary pulmonary hypertension (PHT) among hemodialysis patients and search for possible etiologic factors. The prevalence of PHT was prospectively estimated by Doppler echocardiogram in 62 long-term hemodialysis patients on the day post dialysis. PHT (> 35 mm Hg) was found in 32 (51.6%) patients with a mean systolic pulmonary artery pressure of 39.6 ± 13.3 mmHg. The hemoglobin and albumin levels were significantly lower in the PHT subgroup (11.1 ± 1.86 vs 9.8 ± 1.97 g/dL and 3.75 ± 0.44 vs 3.38 ± 0.32 g/dL, p = 0.01 and 0.02, respectively). Our study demonstrates a surprisingly high prevalence of PHT among patients receiving long-term hemodialysis. Early detection is important in order to avoid the serious consequences of the disease