The aims of our study were to determine concentrations of wasted halothane in operating rooms and to investigate the effect of halothane pollution on liver functions of exposed personnel. The studied group included operating room personnel from the clinic of surgery, Novi Sad University Clinical Center. Surgeons were exposed to an average concentration of 29.41 mg/m³, anesthesiologists to 34.60 mg/m³, instrumenting nurses to 28.62 mg/m³ and anesthetists to 30.09 mg/m³ of halothane. Anesthesiologists in 32% of operations were exposed to a concentration higher than the threshold limit value, surgeons in 23%, instumenting nurses in 22% and anesthetists in 18% of operations. Laboratory values of the liver function indicators in the exposed group were significantly worse than in the control group. The results suggest that exposure to wasted halothane may be harmful to the livers of operating room personnel.