Background: Inflammation plays a major role in the development and progression of gastric and other gastrointestinal tumors. The IL-17 family of cytokines has been under investigation as targets of immunotherapy. Materials and Methods: We investigated the levels of IL-17A inflammatory cytokine in the sera of 57 patients with gastric cancer (GC) and 90 healthy age/sex matched controls using ELISA methods. Results: In only 5 (8.8%) of the patients' sera was IL-17A detectable. No IL-17A was apparent in the sera of healthy controls. The maximum concentration of IL-17A in patients was 7.004 pg/ml. Vascular and lymphatic invasions were only seen in one of the 5 positive cases. Although all of them were in the age group >60 years, no correlation was seen between age and IL-17A level. These results are somewhat different from our findings for colorectal cancer (CRC) in the same population. Conclusions: It is possible that the inflammopathology of CRC and GC are rather different, at least in Fars, a southern province of Iran.