This quasi-experimental study examined the effects of Cognitive Behavioral Group Therapy (CBGT) in alleviating anxiety and enhancing emotion regulation in community-sample Thai middle school students. Forty-seven community-sample students in Grades 7–9 with elevated SCARED scores participated in this pre-post treatment–control study. Twenty-three in the treatment group attended the eight-session 2-hour semi-weekly CBGT. The remaining were the control group. Before and after the intervention, the participants completed the measures of anxiety and emotion regulation. Data obtained were subsequently analyzed using repeated-measures and between-groups MANOVAs. At post-intervention, the treatment group reported a significant decrease in anxiety but a significant increase in emotion regulation. Furthermore, when compared with the control group, their anxiety score was significantly lower but their emotion regulation score was significantly higher, respectively. Findings supported the benefits of CBGT in reducing anxiety in Thai middle school students and in enhancing their emotion regulation skills. Therapeutic implications for anxiety reduction were discussed.