The purpose of this paper is to evaluate the validity and reliability of Cognitive Therapy Group Intervention (CTGI) which focuses on the elements of resilience among adolescents with behavioural problems. It is developed based on Cognitive Theory (comment: it’d be more sufficient if you can mention whose theory) and Sidek Module Development Model and consists of eight interventions. Cognitive Therapy Intervention (CTI) manuscripts and a five-item questionnaires were distributed to five content experts to determine the intervention’s validity. The findings reported the validity index of 0.87. The target group were thirty-two adolescents chosen to measure the reliability of each intervention by evaluating the objectives in each intervention session. As a result, a reliability index of 0.85 was obtained. From these two indexes, it is proven that the Cognitive Therapy Group Intervention (CTGI) possesses high validity and good reliability and is ready to be put to use. This implies that, counselling interventions in schools are required in working with adolescents with at risk behaviours.