Background and aims. Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver pathology worldwide and is strongly associated with obesity and insulin-resistance and food intake. Nesfatin-1 is a new peptide that controls appetite and food intake. The objective of this research was to examine the serum concentrations of nesfatin-1 in NAFLD. Material and methods. Thirty NAFLD patients who had elevated liver enzymes and 40 age-and sex-matched healthy subjects were included in this study. NAFLD was diagnosed and graded with the findings of liver ultrasound scan. Nesfatin-1 concentrations were measured using an ELISA method and the relationship between nesfatin-1 and metabolic parameters were investigated. The subjects were divided into two groups according to their body mass index (≥30 and <30) and nesfatin-1 concentrations were examined between both groups. Results. Serum nesfatin-1 concentrations in NAFLD patients were lower than healthy controls (0.26±0.14 ng/ml, 0.38±0.18 ng/ml, respectively, and p 0.008). We found a negative correlation between nesfatin-1 and fasting glucose and body mass index. In obese subjects, serum nesfatin-1 concentrations were significantly lower when compared with non-obese subjects (0.26±0.12 ng/ml, 0.37±0.19 ng/ml, respectively; p 0.014). In addition, we showed that nesfatin-1 concentrations in subjects with insulin resistance were significantly lower in comparison with insulin-sensitive ones (0.27±0.17 ng/ml, 0.38±0.17 ng/ml, respectively; p 0.015). Conclusion. Our study has shown that nesfatin-1 concentrations were reduced in NAFLD. The results of this study indicate that nesfatin-1 may have a significant role in NAFLD. © 2012 Informa Healthcare.