Although most notorious as a liver carcinogen, the mycotoxin aflatoxin B1 targets other tissues as well, including those of the respiratory system. Because the biotransformation of aflatoxin B1 to toxic and nontoxic metabolites has been fairly well characterized, it serves as a useful and relevant model carcinogen for studying the biochemical (i.e., balance between bioactivation and detoxification) and molecular (i.e., mutations in target genes) mechanisms of pulmonary chemical carcinogenesis. Because of the cellular diversity of the lung, it is of particular interest to assess these processes in different lung cell types, if we are to identify the target cells for carcinogen action. This review summarizes studies that have been aimed at identifying the basis for susceptibility of the lung to aflatoxin B1.