The effect of prenatal exposure to alcohol on the development of basal heart rate and on the elicitation and habituation of the heart Tate orienting response was examined in three experiments with rats. In all experiments, Etoh dams consumed large, daily amounts of alcohol and their weight gain during pregnancy was less than that of ad lib or pairfed dams. In addition, Etoh-exposed pups weighed less and grew more slowly than their ad lib or pairfed counterparts. Although prenatal exposure to alcohol had a significant effect on the ontogeny of basal heart rate, there was no effect on the magnitude of the heart-rate response to a novel olfactory stimulus or on habituation of the heart-rate response to that stimulus. Implications of the present findings for models of alcohol-induced attention deficits are discussed.