There are limited evaluations of an evidence-based parenting program for parents from large developing countries, such as Indonesia. This study aimed to test the efficacy and acceptability of an evidence-based parenting program, the Triple P seminar series, among Indonesian parents. The level of child emotional and behavioral problems was the primary outcome of this study. Participants were 143 parents of children aged 2-12 years in Indonesia that were randomly allocated into the intervention (n = 72) or waitlist control group (n = 71). Participants, investigators, and data collectors were not blinded to the group assignment. A randomized-controlled trial was conducted with 143 parents of children aged 2-12 years in Indonesia. Results showed that parents in the intervention group reported a greater decrease in child behavioral problems (d = 0.45), dysfunctional parenting practices (d = 0.69), parental stress (d = 0.44), and a greater increase in parenting confidence (d = 0.45) in comparison to parents in the waitlist control group at post intervention. The intervention effects were maintained at 6-month follow up for parents in the intervention group. The program was deemed to be culturally appropriate as parents indicated high levels of acceptability and satisfaction with the program content. It is suggested that future studies include families with lower income and employ a more stringent design (e.g., using validated measures, multiple facilitators, and blinding).