The present study was carried out to investigate the potential toxicity of dimethyl disulfide by a 2-week inhalation in F344 rats. The test article, dimethyl disulfide, was exposed by inhalation to male and female rats at dose levels of 0, 33, 100, or 300 ppm/6 hrs/day for 2 weeks. At the end of treatment period, all males and females were sacrificed. During the test period, clinical signs, mortality, body weights, food consumption, hematology, serum biochemistry, and gross findings were examined. The mean body weights of the male 300 ppm group and the female 33 ppm or higher dose groups were significantly lower than those of the control group, respectively. The mean food consumption at male 300 ppm and female 100 and 300 ppm were significantly decreased compared with the controls. Some treatment-related serum biochemical changes, including decreased alkaline phosphatase at male 300 ppm and female 100 and 300 ppm, reduced total bilirubin at male 300 ppm, and decreased alanine aminotransferase at female 300 ppm, were observed in a dose-dependent manner, but these findings were considered to be of no toxicological significance. There were no adverse effects on mortality, clinical signs, hematology, and necropsy findings in any treatment group. Based on these results, it was concluded that the 2-week repeated dose of dimethyl disulfide by inhalation resulted in suppressed body weight gain and decreased food consumption at the dose of male 300 ppm and suppressed or reduced body weight gain and decreased food consumption at the dose of female 33 ppm or higher. In the present experimental conditions, the no-observed-adverse-effect level (NOAEL) was considered to be 100 ppm/6 hrs/day for male rats and below 33 ppm/6 hrs/day for female rats.