Abstract Background and Aims Iron deficiency is pervasive among hemodialysis (HD) patients; however, although transferrin saturation (TSAT) of <20% and/or serum ferritin of <200 ng/mL should express iron scarcity, in HD patients high ferritin levels could be related to inflammation rather than reflecting optimal iron stores. Omentin-1 is an anti-inflammatory adipokine that is also involved in regulation of iron metabolism through binding with lactoferrin. In this pilot study, we aimed at evaluating serum levels of Omentin-1 in a small HD population, in order to determine its possible relationships with iron status. Method Omentin-1 was measured by ELISA in serum samples of 33 chronic HD patients before a single mid-week HD session and at 1h, 2h and 3h after dialysis start. Common biochemical and clinical parameters were also recorded. Results Serum omentin-1 levels were statistically higher in HD patients than in matched healthy controls (763 [367-1423] vs. 371 [228-868] ng/mL; p=0.03). Omentin-1 levels were broken down after the first hour of HD (reduction ratio: 45±5%) and tended to get back to baseline after the third hour (p=0.04). Correlation analyses showed omentin-1 levels to be directly associated with serum iron (R=0.380; p=0.03), ferritin (R=0.843; p<0.001), TSAT (R=0.661; p<0.001), serum amylase (R=0.454; p=0.01), ALT (R=0.380; p=0.03) and inversely with serum phosphate (R=-0.403; p=0.02), troponin (R=-0.443; p=0.01) and transferrin (R=-0.390;p=0.04). At ROC analyses, Omentin-1 levels showed a remarkable capacity to discriminate HD patients with iron deficiency (TSAT<20%) with an AUC of 0.830 (95%CI 0.658 to 1.000; p=0.002. best cut-off value: ≤478.8 ng/mL; sens. 75%; spec. 85%). Of note, such discriminatory capacity was even better than that of serum ferritin (AUC 0.739; 95%CI 0.528 to 0.950; p for differences between AUCs=0.04; Figure 1) Conclusion Findings from this pilot study demonstrate that HD patients have altered Omentin-1 values probably because this protein is involved in the maintenance of iron equilibrium. Larger studies are needed to confirm whether Omentin-1 might be proposed as a new tool in the assessment of iron deficiency and in the management of iron therapy for HD patients.