Purpose: The study was aimed to assess the competency and professional attitude of school health nurses who are occupied with adolescent health, and to provide basic information for the development of continuing education programs for them to improve their competencies. Method: The self-reported questionnaire based on WHO assessment tool were used to assess the competencies of the school health nurses providing health care for adolescents. The subjects were 584 school health nurses and the data were collected from January 28 to March 5, 2002. Result: The school health nurses in middle schools showed significantly higher scores than the school health nurses in primary schools on the level of competency. The nurses were scored the highest in the area of dealing with sexual issues for the students, followed by providing them direct care and application of primary care concept to the field of school health nursing. The areas showing the lowest scores were counseling and utilization of the system. There was a significant positive correlation between competency and professional attitude of the school health nurses. Conclusion: Based on the results of this study, it is necessary to develop various continuing educational programs for school health nurses using different teaching methods such as web-based program.