PURPOSE: This studywas designedto construct andtest astructural equation model for life satisfaction in grandmothers who were parenting grandchildren METHODS: Grandmothers assuming part-time parenting responsibilities for grandchildrenwererecruitedinfourcities inSouthKorea. Theywere asked to complete a questionnaire through face to face interviews or self reports, and 248 data units were analyzed with Structural Equation Modeling. RESULTS: Model fit indices for the final model revealeda fit at anexcellent level, andall of the 12 paths were statistically significant explaining 51% of the variance. Predictors of life satisfaction in the final model were parenting efficacy, perceived health status, parenting stress, amount of parenting, anddemographic factors. The newfindingsof thisstudy were asfollows: First, thesatisfactionwithlife of part-time parenting grandmothers was less than that of non-parenting grandmothers. Second, parenting stress and parenting efficacy revealed determinants to life satisfaction. Third, motivationof parentingand amount of parenting affect both parenting stress and parenting efficacy. CONCLUSION: The value of parenting and the grandmother-adult children relationship quality should also be considered in developing a grandmothers' educational program, because these are the factors which strengthen parenting efficacy and alleviate parenting stress.