Renalase, secreted by the kidney, degrades catecholamines and may play a role in the regulation of sympathetic tone and blood pressure. The aim of this study was to assess serum renalase levels in hemodialysis patients and their relationship to blood pressure control, type of antihypertensive therapy and the presence of residual renal function. <b><i>Results:</i></b> The mean serum renalase in the study cohort was significantly higher than in the control group (27.53 ± 7.18 vs. 3.86 ± 0.73 µg/ml, p < 0.001). The serum renalase concentration was significantly lower in patients with residual renal function when compared to the anuric patients. The type of hypotensive treatment (β-blockers, ACE inhibitors or AT1 receptor blockers) did not affect renalase levels. There was a significant inverse correlation between the serum renalase and age (r = –0.28, p = 0.023) and residual renal function (r = –0.327, p = 0.001). Renalase was not related to blood pressure, heart rate or hemodialysis vintage. <b><i>Conclusion:</i></b> Elevated renalase levels in HD patients may be due to<b> </b>impaired kidney function. Further studies are needed to prove or disprove the possible role of renalase in the pathogenesis of hypertension in patients with kidney diseases.