PURPOSE: This study was conducted to develop and test effects of a child health management program based on cooperative learning for mothers of preschool children. METHODS: For this quasi-experimental study, a nonequivalent control group pretest-posttest design was used. Outcome measures were level of child health management self-efficacy, child health management practices, child's health behavior. Participants were 55 mothers (experimental group 28, control group 27). The program was composed of 6 categories of home health management for preschool children, and provided for three 120-minute sessions. Data were collected from September to October, 2015, at 3 times: baseline, 3 and 6 weeks after beginning the intervention. Data were analyzed using SPSS/WIN 21.0 program. RESULTS: After 3 and 6 weeks, there were significant differences between the two groups in child health management self-efficacy (F=18.33, p<.001), child health management practices (F=8.91, p<.001), and child's health behavior (F=9.91, p<.001). CONCLUSION: Study findings indicate that this child health management program based on cooperative learning is effective and can be recommended as an intervention for mothers of preschool children. It will contribute to enhanced child health management self-efficacy and health management practices and improved child's health behavior.