Background: Since positive parenting program (Triple-P) is one of the ways to improve parentchild interaction, conducting a meta-analysis will help determine its effect size. This study aimed to use meta-analysis to examine the effect of level 4 Triple-P on parent-child interaction with special needs in Iran. Methods: The current study is a meta-analysis review study. Before analyzing the effect size of the mean differences, the PRISMA (preferred reporting items for systematic reviews and metaanalyses) method was used to investigate the decision tree model. Then, the effect size of Triple-P was investigated using the meta-analysis method. Twelve studies (out of the 37) were collected with the keywords “, Triple-P”,and “, parent-child interaction”,from Google Scholar, IranDoc, IranMedex, Magiran, and SID according to the inclusion and exclusion criteria. They were conducted in Iran during 2012-2021 and were analyzed through meta-analysis. The inclusion criteria of the articles included written in Persian, having a control group, being interventional, and using original data. The exclusion criteria included duplicate articles and non-compliance with the title with Triple-P level 4. The study instrument was a meta-analysis checklist. Funnel plot, fail-safe number, and Cochran Q test were used to assess the publication bias, expected confidence, and effect size heterogeneity, respectively. The obtained data were analyzed by comprehensive meta-analysis (CMA) software. Results: Findings showed that the effect size of the mean difference rate of level 4 Triple-P on parent-child interaction was 0. 59 (P<0. 0001), which is medium according to the Cohen table. Fisher’, s z indicated a low standard error and no publication bias. The value of the Q test is significant, and the effect sizes are heterogeneous (P<0. 0001). Conclusion: Given the moderate impact of level 4 Triple-P, this method of parenting program can play an important role in improving the interaction of parent-child with special needs.