Chlordimeform is a member of the formamidine class of insecticide/acaricide with many diverse pharmacological actions. Little is known, however, about its behavioral actions, although evidence suggests that it produces signs of central nervous system stimulation. The present study was undertaken, therefore, to further characterize the behavioral actions of chlordimeform. A flavor-aversion paradigm was selected because paradigms of this sort have already proven useful in assessing the behavioral impact of other types of toxic substances, e.g., methyl mercury lead and triethyl-tin.