Postnatal depression is the most frequent psychiatric disorder seen after childbirth, with a prevalence rate of 10% to 15%. The women at risk need to be identified by a valid and reliable method, either using a screening instrument or an interview schedule. The preventive strategies need to have enough power to detect a clinically worthwhile effect to be considered useful in clinical practice. Many of the risk factors for developing postnatal depression are present during the pregnancy and immediate post-partum period. The risk factors for postnatal depression include depression or anxiety during pregnancy, experiencing stressful life events during pregnancy or the early puerperium, maternity blues, low levels of social support, past history of depression and poor marital adjustment. The antenatal and postnatal period provides an ideal opportunity to screen women for these risk factors. The women identified to be at risk can be identified, and preventive interventions can be implemented. Routine clinical practice can be improved to identify some of the women at risk by better communication between health professionals. There are no antenatal screening tools that have been shown to be of benefit in predicting postnatal depression. Edinburgh Postnatal Depression Scale is widely used in the postnatal period to screen for depression. The psychosocial interventions to prevent postnatal depression have not been shown to be beneficial and there is a dearth of psychopharmacological trials to make firm conclusions about their efficacy in preventing postnatal depression. Individualised psychosocial interventions aimed at the at-risk populations and initiated in the postnatal period appear to have some benefit in preventing postnatal depression. The focus of this article will be the risk factors associated with postnatal depression, screening methods and tools to identify those at risk of developing the disorder and the psychosocial, psychological and psychopharmacological interventions to prevent postnatal depression.