Although bismuth is widely used as a lead substitute in the industrial field, the toxicity of bismuth by inhalation is little known. We performed a 13-wk intratracheal intermittent bismuth dose toxicity study. Bismuth was administered at dose levels of 0, 0.8, 4, 20 mg/kg to male Crj:CD(SD)IGS rats (SPF) by intratracheal intermittent administration once a week for thirteen weeks to investigate its potential toxic effects; especially for specific adverse effects and changes related to pre-neoplastic lesions. Our results showed foreign body inflammation in the lungs, which was caused by intratracheal administration of bismuth, and physical changes related to pulmonary lesions; however, there were no serious changes in other organs. We concluded that dose-dependent, but not specific adverse effects, were attributable to bismuth inhalation in the rat.