Greater knowledge of the process by which postpartum parents acquire further awareness of their child and fulfill parental roles will likely lead to an understanding that creates a new approach to nursing. This study explored the transition to parenthood and the relationship between parenthood and family functioning in first-time mothers and fathers. Seventy-eight parents (41 mothers, 37 fathers) participated in the study and completed the Scale of Early Childrearing Parenthood and Family Assessment Inventory at birth and at 1, 3, 6, and 12 months postpartum. The levels of parental role attainment and awareness of the child rose dramatically between birth and 3 months postpartum, thereafter stabilizing up to 12 months postpartum. Parenthood and family functioning showed a moderately positive correlation, which gradually became more positive over time. Appropriate nursing interventions might be necessary for parents who show difficulty in accepting their parental roles and have low levels of awareness of their child after 3 months postpartum. Such intervention might be necessary for not only the parents, but also the family unit.