© 2015, Springer Science+Business Media New York.Background: Inflammatory cytokines modulate immune responses in the tumor microenvironment during progression. The role of interleukin (IL-17) in cancer is currently under debate. This study was conducted to investigate the serum levels of IL-17 in patients with pancreatic adenocarcinoma (PA) and the relationship with tumor progression and known prognostic parameters. Material and Methods: Thirty-five patients with PA were investigated. Serum samples were obtained on first admission before treatment and follow-up. Both serum IL-17 levels were determined using enzyme-linked immunosorbent assay (ELISA). Age- and sex-matched 35 healthy controls were included in the analysis. Results: The median age at diagnosis was 61 years, range 38–84 years; 21 (60 %) patients were men. The tumor was located in the head of pancreas in 24 (69 %) patients. The most common metastatic site was liver in 20 patients with metastasis (n = 18, 90 %). The median follow-up time was 24.0 weeks (range 1.0–191.0 weeks). At the end of the observation period, 12 (34 %) patients experienced disease progression and 23 patients (66 %) were dead. Forty-four percent of 18 metastatic patients who received palliative chemotherapy (CTx) were CTx-responsive. Median progression-free survival and overall survival of the whole group were 13.7 ± 2.3 weeks [95 % confidence interval (CI) = 9–18 weeks] and 48.0 ± 12.8 weeks (95 % CI = 23–73 weeks), respectively. The baseline serum IL-17 levels were significantly higher in patients with PA than in the control group (p = 0.001). Moreover, serum IL-17 levels were significantly higher in the patients with large pathologic tumor status and low albumin levels (p = 0.04 and p = 0.03, respectively). However, serum IL-17 assays had no prognostic roles on outcome. Conclusion: Although serum levels of IL-17 assays were found to be diagnostic value, no predictive and prognostic value was determined in PA patients.