The detection of postpartum depression (PPD) is an important public health issue because of its negative consequences on both the mother's and the infant's health. Up to now, one of the major difficulties is to find a simple and valid instrument able to detect women at risk to develop PPD already during pregnancy. The present article describes a short, simple questionnaire that was developed in Geneva, the Questionnaire de Dépistage Anténatal du risque de Dépression du Postpartum (DAD-P), previously named le Questionnaire de Genève. The authors propose a preventive strategy and follow-up that can be used by any health professional working with pregnant women.