Adipokines have a significant effect on metabolism, immunoinflammatory responses as well as on carcinogenesis; therefore, we aimed at evaluating their potential predictive and prognostic significance in lung cancer. Eighty patients--mean age 62.9 ± 9.2 years--with previously untreated lung cancer (61 NSCLC and 19 SCLC) of all stages and 40 healthy individuals were enrolled in this study. Serum levels of leptin, adiponectin and ghrelin were measured using human Radioimmunoassay kits. Serum leptin levels in lung cancer patients were lower compared to control (p < 0.0001), while adiponectin and ghrelin levels were significantly increased in patients (p = 0.0003 and p = 0.0043, respectively). Additionally, the leptin/adiponectin ratio was significantly lower in the patients group compared to controls (p < 0.0001]. There was no association between serum levels of adipokines and any of the patient clinicopathological characteristics or response to therapy. Nevertheless, patients with lower values of serum leptin had shorter overall survival (p = 0.014), whereas multivariate analysis revealed leptin levels as an independent prognostic factor for survival (p = 0.024, HR 0.452, CI 95 % 0.232-0.899). These results suggest that adipokines may play a role in the pathogenesis of lung cancer, while leptin serum levels might provide useful prognostic information.