AbstractThe purpose of this study was to test the hypothesis that mothers with depressed mood would exhibit less optimal interaction than their nondepressed counterparts and that their infants would show similar deficits in interactional behavior. Twenty‐two mothers and their 2‐month‐old infants were videotaped in to‐minute free‐play segments in a laboratory playroom, and their interactions were coded using both time‐sampling and global clinical ratings of behavior. Mothers with depressed mood were judged significantly lower on overall positive interaction, Expressivity/Affective Involvement, and Responsivity/ Sensitivity than were nondepressed mothers. Infants of mothers with depressed mood were rated significantly lower than infants of nondepressed mothers on corresponding interaction domains. Mothers with depressed mood were also rated as more variable than nondepressed mothers along a continuum of withdrawal to controlling/intrusive behavior. Contrary to prediction, level of maternal stimulation and infant activity did not differ as a function of depression in maternal mood. We conclude that mild to moderate symptoms of maternal depression may have salient but selective effects on mother‐infan