Diverse studies suggest that interleukin-6 (IL6), as a member of cytokines family, has a major role in inflammatory processes of airways and lungs. In this study, an attempt was made to determine the serum level of IL6 in sulfur mustard (SM) injured patients and its comparison with controls. The measured IL6 mean level in patients with chemical injuries (0.76±0.3 ng/ml) was significantly higher than the control group’s mean level (0.34±0.12 ng/ml). Furthermore, patients with moderate to severe symptoms had a serum level of (0.95±0.92 ng/ml) which was significantly higher than mild (0.47±0.54) and control (0.34±0.12) groups.The outcome of this research program demonstrates that an increase in serum level of IL6 can have a role in pulmonary complications of SM, similar to other well defined pulmonary diseases. However, further studies are required to clarify the role and mechanism of IL6 in such patients.