The left frontal brain region is specialized for expression of positive emotions (e.g. joy) whereas the right frontal region is specialized for negative emotions (e.g. sadness). Depressed adults have been found to exhibit reduced left frontal electroencephalographic activity. In this study, baseline frontal and parietal EEG activity was measured in 13-15-month-old infants of depressed and nondepressed mothers who were of middle income with no other major psychiatric problems. Compared to infants of nondepressed mothers, infants of depressed mothers exhibited reduced left frontal EEG activity. Infants of mothers with major depression exhibited lower levels of left frontal EEG activity than those of mothers with subthreshold depression.