One way in which to tackle the profound change in the cultures and practices of working with children towards a system organized around children, young people, and families with a sharper focus on prevention and early intervention is a more positive, rigorous, and confident sharing of expertise. Expertise is seen as crucial to the safeguarding process in relation to child abuse cases. However, expertise should not be the exclusive domain of professionals and should encompass children and their families as experts on their own lives. This paper presents insights into expertise from an analysis of findings from two studies commissioned in Wales. The studies comprised 18 serious case reviews and 2 administrative reviews representing all of the serious child abuse cases submitted centrally to Wales between 1996 and 1998. From the analysis, themes emerged about the use of expertise in two areas: (1) expertise about the child and the child’s development in their social context and (2) expertise about the parenting that the child received and factors that could impact the parents or caregivers' ability to offer safe nurture and care. In having genuinely shared expertise and responsibility, the following mechanisms were recommended offering more efficient use of expertise: (1) a more rigorous approach and clearer use of expertise and a more systematic process of assessment; (2) a lead professional playing a key role in piecing information together, seeing gaps, and coordinating expert knowledge for a better understanding to be achieved; and (3) the fostering of professional competence and confidence. Table, figures, and references