This paper examines the issues that nurses experience when entering the family system to work preventively. The theoretical basis of family-centered nursing is analysed and the need for empirical work is identified in order to develop a knowledge base for this practice. Some unique characteristics of the public health nursing role are discussed with emphasis on territorial issues, power relationships and accountability problems. The need for public health nurses to function as advanced generalists across different system levels is recommended and family skills necessary for effective family nursing are examined. The authors identify the unique role of public health nurses because they have access to healthy families and families dealing with early stages of health concerns. The authors support the general structure of public health practice as of value for preventive work with families. However, clarity regarding referrals, contracting and the rights of clients is called for to facilitate collaborative family-centred nursing.