A comprehensive evaluation of intergenerational programming (IGP) is needed to identify best practices. In this study, I conducted an IGP evaluation whose first purpose was to explore the effectiveness of IGPs through a meta-analysis of programs reported in the literature between 2000 and 2016. I first examined the effect of IGPs on older adults’ depressive symptoms, self-esteem, and life satisfaction separately, and then combined them into a single indicator of psychological well-being. The second aim of the study was to identify possible moderators that might affect the success of IGPs with older adults, including IGP characteristics such as activity type (social activity or personal-related activity), serving type or intended purpose (who is serving whom—older adults’ participation benefitting younger participants or vice versa), ratio of older to younger participants, IGP duration (i.e., program length, intervention time per session, number of sessions, and interval between two consecutive sessions), program support (who is facilitating the interaction between younger and older adults), and participant characteristics (i.e., younger and older participants’ age). Fifteen studies with 625 older adults were included in the study, and the Hunter and Schmidt (2004) meta-analytic approach was employed to perform the analyses. The results indicated that IGP participation was related to enhanced life satisfaction and self-esteem and reduced depressive symptoms among older adults. Pooling these effects into one construct representing psychological well-being (d = 0.37, 80% credibility interval = [-0.27; 1.00]), I found that IGP was indeed effective for older adults’ psychological well-being but not significant. Overall, the effect of IGP was positive; however, the effectiveness was variable, implying the possibility of moderating factors that indeed produce the effectiveness. Due to the limited number of studies, moderator analysis was not conducted; however, the relationships among IGP characteristics, participant characteristics, and IGP effect size were explored through scatterplots, correlations, analysis of variance (ANOVA), independent samples t-test, and sample-weighted regression analyses. Of note, younger participants’ age (r = 0.64, p<.05) was significantly related to the higher IGP effectiveness. Additionally, I tried to investigate the effect of IGP on younger participants; however, due to the variety of IGP outcomes, I was only able to present the effect sizes of younger participants for individual studies. For future researchers, more investigation regarding IGP effects on younger individuals and more quantitative and comprehensive research utilizing consistent reporting and coding procedures is needed to better understand the overall IGP effectiveness and identify the best practices.