Objective: The aim of this review was to explore the unique contribution of shame (negative evaluation of the self) and guilt (negative evaluation of behaviour) to postnatal psychological symptoms. Background: Although shame and guilt are related to psychological symptoms, the separate effect of each in postnatal psychological symptoms are not yet known. Methods: Seven electronic databases were systematically reviewed for articles on: (1) quantitative measures of shame, guilt, and psychological symptoms (2) in the postnatal period for infants under two years of age (3) published in English. Results: Of the 1,615 articles retrieved using PRISMA guidelines, five met criteria and were analysed independently by two reviewers using the STROBE criteria. In mothers, shame was significantly related to stress and postnatal depression. Shame significantly predicted postnatal depression. Guilt was significantly related to postnatal depression; however, the relationship was substantially reduced when included with shame. In fathers, shame, but not guilt, was significantly related to stress, anxiety, and depression. Conclusion: Shame and guilt are trans-diagnostic phenomena, negatively impacting on postnatal psychological health, and potentially the parent-child relationship. More research is needed to develop awareness of the unique effects of shame and guilt to optimise perinatal intervention.