Objectives The purpose of this study is to empirically analyze the growth mindset related to learning outcomes of adult learners participating in lifelong education programs, the structural relationship between self-directed learning ability, and the partial mediating effect of self-directed learning ability in the relationship between growth mindset and learning outcomes. Methods In order to solve the research purpose and research problem, 308 adult learners who are taking lifelong education program in university located in G city of Gyeongsangbuk-do were selected as research subjects. A sur-vey was conducted by selecting growth mindset as an independent variable, self-directed learning ability as a me-diating variable, and learning outcomes as a dependent variable. The collected data were analyzed using SPSS & AMOS 29.0 program for reliability verification, correlation, multiple regression analysis, confirmatory factor analy-sis, and covariance structure analysis. Results The potential variables of growth mindset, self-directed learning ability, and learning outcome perceived by adult learners showed a significant positive relationship, and the structural relationship between growth mind-set, self-directed learning ability, and learning outcome was also significant. In addition, it was confirmed that self-directed learning ability has a significant effect as a partial mediator in the relationship between growth mind-set and learning outcomes. Conclusions Growth mindset and self-directed learning ability are core competencies that adult learners should cultivate. Therefore, in order for adult learners who have accumulated life experiences for a long period of time and whose learning tendencies are fixed to adapt to the changing times and live a successful second life, it is neces-sary to find ways to strengthen growth mindset and self-directed learning ability.