The two most common gas inhalation injuries encountered in emergency departments are carbon monoxide and chlorine inhalations. In this study, chlorine was produced through a method different to the previous experimental models. Rats were subjected to inhale chlorine, after which the effects of N-acetylcysteine on pulmonary damage were evaluated. A total of 50 rats were equally divided into five groups. Group 1 received nothing. Groups 2 and 3 were taken as 6 h, groups 4 and 5 as 24 h control and N-acetylcysteine groups, respectively. Firstly, 200 ppm chlorine gas was given for 20 min. Then, 40 mg/kg N-acetylcysteine was given intraperitoneally. The same procedure with the same dose was repeated 3 h later. The same procedures were applied to the control group but this time saline was used. Tissue samples of lungs were taken. Glutathione levels of the rats in the N-acetylcysteine group sacrificed at 24 h were significantly higher than those of the control group. Histopathological evaluation of the pulmonary tissues of the rats sacrificed at 6 and 24 h revealed mild-to-moderate degrees of tissue damage. The degree of tissue damage at 6 h and 24 h N-acetylcysteine group rats was lower than that in the control group. As a result, tissue damage resulting from experimental chlorine inhalation can be alleviated by N-acetylcysteine. This is mainly the result of the antioxidant effects of the N-acetylcysteine.