The effects of perinatal diazepam exposure of rats on stress-induced metabolic activation of the mesotelencephalic dopamine (DA) system were examined. Footshock stress parameters were selected such that DA turnover was increased in the prefrontal cortex and certain mesolimbic dopaminergic regions; a stress-induced activation of striatum was not observed. Perinatal treatment with the anxiolytic benzodiazepine diazepam (days E8 through the first week after gestation) did not alter basal dopamine turnover in the prefrontal cortex or striatum, or in any of the mesolimbic sites examined except for the nucleus accumbens and ventral tegmental area (in which turnover was decreased). However, perinatal exposure to diazepam significantly reduced the magnitude of the stress-elicited increase in prefrontal cortical dopamine turnover, and conversely resulted in a stress-induced enhancement of turnover in the striatum. These data suggest that although perinatal exposure to diazepam may alter basal dopaminergic function in some regions, certain enduring changes in dopamine function in other mesotelencephalic DA sites are revealed only under conditions that result in perturbation of central dopamine neurons, such as environmental stress. These data also suggest that perinatal benzodiazepine exposure may be reflected in the adult in a decreased ability to cope with stress.