Aim: The overall aim of this thesis is to explore School health nursing through school nurses’ descriptions of schoolchildren’s health and to analyse factors influencing the recording of school-children’s health in the School Health Record (SHR). An additional aim is to evaluate fam-ily nursing interventions as a tool for the school nurses in the School Health Service (SHS). Methods: The thesis comprises four papers. A combination of qualitative and quantita-tive methods was used through individual interviews with a strategic sample of school nurses (n=12) (PI), a national survey to a representative sample of school nurses (n=129) (PII, III) and the implementation of family nursing models developed in Canada with girls in their early ad-olescence with recurrent health complaints and their families (n=4) in co-operation with their school nurses (n=2) (PIV). The Strengths and Difficulties Questionnaire (SDQ) was used as pre and post test. Evaluation interviews were conducted with the families and the nurses separate-ly. Qualitative content analyses were used to analyze the interview text with the school nurs-es and the families. Manifest content analysis was used to analyze the free text answers of the survey and the evaluation interview with the school nurses. Descriptive statistical analyses were used to describe demographic data in all four papers. The SDQ was hand-scored statistically. Findings: The findings showed that nurses judged the schoolchildren’s mental health as dete-riorated, especially in socially disadvantaged areas and more generally among girls expressed as psychosomatic symptoms. Individual factors related to lifestyle affected the schoolchildren’s physical health, and the mental health was, to a large extent, affected by the school environ-ment and family relations. The latter seemed to be the most important factor affecting school-children’s mental health. The basis for the school nurses judgement of the physical health was health check-ups and the health dialogues. Spontaneous visits were more commonly used to judge the mental health. Recording schoolchildren’s mental health was a challenge for school nurses. Difficulties were related to ethical considerations, tradition, lack of time and the im-proper structure of the SHR. Fears of marking the schoolchild for life related to the schoolchild itself, the parents or to other authorities/successive caregivers were brought up as hinders for recording mental and social health. Family sessions may be useful within the profession when handling recurrent health complaints among adolescence girls. The girls and their families ex-perienced relief, they felt confirmed and that their feelings and reactions were normal in that situation. The families became aware of their own strengths and possibilities and this was sup-ported by the SDQ which showed an increased well-being. The school nurses valued this way of working and meant that the sessions seemed to start a changing process within the families. Conclusions: The results indicate that school nurses have a deep knowledge about schoolchil-dren’s health which is not used to its full potential in a public health perspective. However, the experienced difficulties recording schoolchildren’s mental health seem obvious, which would de-mand developing the SHR for the needs of today. Family sessions in SHS with the school nurse as a collaborator with the family seemed useful and may be transferable to other health problems expressed by the schoolchildren. Bronfenbrenner’s ecological systems theory and other models for health determinants are used to illustrate the school nurse as a mediator working on the bridge over different health streams with schoolchildren’s health on an individual and a population level.