The hypotheses that exposure of rats to alcohol during a period roughly equivalent to the human third trimester induces changes in social interactions and neurotransmitter and DNA concentrations in the amygdala region were examined. The alcohol exposure was accomplished via an artificial rearing procedure. There were two alcohol-exposed groups (3 and 5 g/kg/day of ethanol) and two control groups (one artificially reared but not exposed to alcohol and one reared normally by dams) in all studies. Active social interactions were reduced in the male 5 g/kg/day group and increased in both female alcohol-exposed groups compared to their respective control groups. Exposure to 5 g/kg/day of alcohol reduced the DNA concentration in the amygdala region of male rats compared to either control group; there were no effects in females. Because some systems have been shown to exhibit alcohol-induced changes only under stressed conditions, noradrenaline, dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured in the amygdala region under both nonstressed and stressed conditions. The stress-induced increase in DOPAC concentrations was enhanced in the female high dose group compared to either control group; there were no effects in males. In summary, alcohol exposure during the early postnatal period altered social interactions and DOPAC and DNA concentrations in the amygdala region in a sexually dimorphic manner.