The current literature on the toxic effects of air pollutants on the tonsils, which are subject to contact with various biological agents and air pollutants, is unsatisfactory. The purpose of this study is to see the effects of anthracite coal briquette gas on the tonsil through the observation of ultrastructural changes of rabbit tonsils acutely and chronically exposed to anthracite coal briquette gas. Electron microscopic examinations revealed definite inflammatory changes, including flattening and loss of microridges and desquamations of surface epithelial cells and loss of desmosomes in the deeper cells in both the acutely and chronically exposed groups.