PURPOSE: The purpose of this study was to investigate the influence of child-care efficacy, job efficacy, and health promoting lifestyle on the job satisfaction of in-home child care helpers who are called Idolbomi. METHODS: Participants for this survey were 153 in-home child care helpers who worked in Seoul. Data were collected from May 23 to October 17, 2014 using self-report structured questionnaires. Data were analyzed using IBM/SPSS 18.0 program. RESULTS: There were significantly positive correlations between child-care efficacy, job efficacy, health promoting lifestyle, and job satisfaction. Stepwise multiple regression analysis revealed that the predictors of job satisfaction were spiritual growth, education level, job efficacy, effect of income. CONCLUSION: Therefore, we need to develop strategies to enhance the job efficacy and health promoting lifestyle of in-home child care helpers to improve their job satisfaction.