During the past decade many researchers have studied the effectiveness of solution-based group counseling in improving characteristics such as self-efficacy, social adaptation, and academic motivation among school age children. Many of these studies have reported significant improvements, yet the exact impact is not known. To estimate this impact, a set of 24 studies meeting the methodological requirements of this study and conducted in high schools from 2007-2017 was selected to be meta-analyzed. The results of this analysis show that the impact is high (0.8) as the treated groups show an improvement of %47. Furthermore, the effect size on solving personal, inter-personal, and academic problems was estimated to be 0.23, 0.57, and 1.57 respectively corresponding to 16.7, 36.6, and 57.5% improvement. It is, therefore, suggested that this approach be utilized more extensively across schools.