Our aim was to study the effects of maternal perinatal mood and maternal emotional availability on child emotional availability and negative affect during the still-face procedure (SFP). The sample included 214 women who participated in a prospective study. We assessed maternal mood problems using the Mini International Neuropsychiatric Interview and PRAQ questionnaire during pregnancy and using STAI and EPDS questionnaires during pregnancy and at 6 months after delivery. Maternal and child emotional availability were studied using the Emotional Availability Scales during the SFP at 6 months. We observed and quantified child's negative affect during SFP episodes. We found that mothers with maternal mood problems (anxiety and/or depression) during pregnancy, but not postnatally, showed less optimal maternal structuring during the SFP, and the children showed lower involvement and responsiveness during interactions with their mothers. Furthermore, lower maternal emotional availability was related to the child's higher negative affect during the SFP. Our findings underline the independent roles of both prenatal stress exposure and maternal caregiving behavior in a child's socioemotional development.