Postpartum depression (PPD) varies worldwide and is considered a serious issue because of its devastating effects on mothers, families, and infants or children. Preterm birth may be a risk factor for PPD. In 2005, the global incidence of preterm birth was estimated to be 9.6%, and of these births, 85% occurred in Africa and Asia. Among Asian countries, Pakistan has a preterm birth rate of 15.7% and the highest prevalence rate of PPD (63.3%). A literature review was therefore undertaken to better understand the potential contribution of preterm birth to PPD and to identify gaps in the scientific literature. Limited studies compare prevalence rates of PPD in mothers of full-term infants and mothers of preterm infants. Furthermore, meta-analyses examining predictors of PPD have not included preterm birth as a variable. The interrelationship between preterm birth and PPD may be explained by early parental stress and mother-infant interaction among mothers of preterm infants. Culture plays an important role in shaping communication between mothers and their infants and defines social support rituals that may or may not mediate PPD. More research is needed to provide evidence for practice.