Health care workers employed operating room in hospital and health centers are unavoidably exposed to inhaling toxic gases, including isoflurane and sevoflurane. Chronic contact with these gases increases the risk of spontaneous abortion, congenital anomalies and cancers. Risk assessment is an important tool in predicting the possible risk to personnel's health. Therefore, this study was conducted with the aim of determining the concentration of isoflurane and sevoflurane gas in the air of the operating room and estimating the non-carcinogenic risk caused by them. In this descriptive-cross-sectional study, according to the occupational method (OSHA 103), 23 samples (isoflurane and sevoflurane) were collected in the air of operating rooms of four selected hospitals in Ahvaz city by using SKC sampling pumps and sorbent tube (Anasorb 747). The samples were determined by used to gas chromatography with a flame ionization detector (GC/FID). Statistical analysis, including the Kruskal-Wallis test, was used to compare the average concentration of anesthetic gases, and the one-sample t-test was used to compare the average with the standard level. In all analyses, the significance level was 0.05, which was performed by SPSS version 22 software. Result of this study showed that the average concentration of isoflurane in private and general hospitals were 23.636 and 17.575 ppm, respectively. Also, the average level of sevoflurane were 1.58 and 7.804 ppm. According to the results the mean amount of anesthetic gases was within the range recommended by Iran's Occupational and Environmental Health Center and the permissible threshold limit provided by ACGIH. In addition, non-cancer risks from occupational exposure to isoflurane and sevoflurane in selected private and general hospitals were acceptable (HQ < 1). Although the results show that overall occupational exposure to anesthetic gases is less than acceptable but long-term exposure to anesthetic gases may endanger the health of operating room staffs. Therefore, it is recommended to implement some technical controls, including regular inspection of ventilation systems, the use of advanced ventilation systems with high cleaning power, continuous control of anesthesia devices in terms of leakage, and periodic training of related staff.