The postpartum period is a time of risk for mood disturbance in women. Postpartum blues occurs commonly, but is self-limited. Postpartum depression occurs in 13% of postpartum women. However, it is estimated that nearly one-half of all cases go undetected. Postpartum psychosis is rare, affecting 1-2 per 1000 women. Postpartum mood disorders can have far-reaching consequences and have been shown to affect the social and psychological development of children. It is critical that healthcare providers understand these disorders and their risk factors to increase detection and to educate women about the risks and treatments of postpartum mood disorders. This review is intended to provide healthcare providers with a better understanding of the descriptive epidemiology, risk factors, and treatments of postpartum mood disorders. The utility of specific screening instruments is also discussed.