Male mice from 19 inbred strains were tested for the effects of nicotine on six responses: respiratory rate, acoustic startle response, Y-maze crosses, Y-maze rears, heart rate and body temperature. Dose-response curves were constructed for each strain on each test in a multitest battery. Results indicated that the responses were strongly influenced by the genotype of the animal. Comparison of the results from the six tests measured in this study and the results previously reported for nicotine-induced seizures in these same strains indicated that the responses could be grouped into two major classes: a set characterized by Y-maze crosses, Y-maze rears and body temperature and a set characterized by seizure sensitivity and seizure latency. Responses observed for respiratory rate and startle response shared characteristics with both of these sets, while nicotine effect on heart rate was fairly unique. The results have identified strains of mice which are differentially sensitive to the effects of nicotine.