BACKGROUND: With 10-15 percent of mothers experiencing postpartum depression this mental health problem is a significant public health issue. One concern is that normal infant development is at risk. Understanding how Postpartum depression impacts on mothering is important knowledge in managing this health problem. OBJECTIVES: To: Explore what is it like to become a mother, and examine how postpartum depression impacts on maternal adaptation. DESIGN: A hermeneutic approach was used guided by the philosophical works of Heidegger and Gadamer SETTING: A relatively affluent metropolitan area, including surrounding rural areas within Australia. PARTICIPANTS: Via purposeful, maximum variation sampling, eleven women who had been medically diagnosed with postpartum depression following childbirth but who were not experiencing psychosis participated in the study. METHODS: In-depth interviews and reflective journaling. RESULTS: Mothers with postpartum depression become "stuck" in a liminal state, an incomplete process of the rite of passage. Therefore, adaptation to the social role of a mother was found to be delayed. Additionally, a delay in becoming competent in parenting skills was evident. A lack of maternal-infant attachment was noted, however, mothers continued to care for their infants but in an unthinking manner that was labelled "mechanical infant caring". CONCLUSIONS: The distress caused by the delay in adapting to being a mother could be addressed by providing a mentor to at-risk women. The mentor should be a mother who has previously recovered from postpartum depression and would act as a symbol of hope. Additionally, on-going education and the insight that occurs during the liminal phase can facilitate mothers with postpartum depression to adapt appropriately.