A review of the literature on the present state of knowledge about the topic "indoor air pollution by smoke constituents" has been made. While consideration is given to standard bibliographic works and more recent reviews, an evaluation of the results of field studies and experimental investigations carried out under realistic conditions is also made. The selection of the tobacco smoke constituents discussed here was based on environmental and toxicological aspects. The following substances are considered in detail: carbon monoxide, nitrogen oxides, formaldehyde, acrolein, ammonia, phenol, hydrogen cyanide, sulfur dioxide, cadmium, nickel, nicotine, some volatile nitrosamines, polycyclic aromatic hydrocarbons, and respirable particulates. The smoke constituent concentrations in the literature are presented in tables. The results are evaluated and discussed with respect to the maximum allowable concentrations presently valid in the Federal Republic of Germany.