Health promoting schools become new trends in the world. School health nurses play an important role in school health practice. They must have the knowledge and skills in implementing health promoting school. The purpose of this study was to investigate the effectiveness of a continuing education program on school health nurses’ attitude and self-efficacy. Using an one-group pretest- posttest design, 127 subjects were participated in this study and received a four hours education program. Self designed questionnaire as measurement and collected data. Data was analyzed by SPSS 10.0. The results showed that there was significant improvement in attitude subscale, but no significant improvement was found in self-efficacy. There were some limits in symposium as education program to promote self efficacy and action research was suggested for further studies to provide more discussion and dialogue.