Starting from a theoretical model for the work of public health nurses, we explored the knowledge, skills, and decision making of Finnish public health nurses in the context of their efforts to maintain and promote child and family welfare. The results indicate that the nurses' knowledge basis and skills cover the concepts included in the theoretical model. The nurses tackle existing situations in the lives of children and their family, attempt to solve the current problems, and together with parents, make collaborative decisions. No attempts are made to produce long-term health care plans. The model seemed to work fairly well in promoting children's welfare, but less so in the case of families. Finnish public health nurses follow the official guidelines governing the work of child welfare clinics, but they set fewer individual goals for children and families.