The treatment or the resocialization is the most important part of the prison sentence which methods can be individual and group. Motivated inmates and less resistance for the treatment are the main precondition for effective treatment. Appropriate behavior of personnel is the main factor for that result. Cognitive-behavioral therapy (CBT) as the most effective evidence based psychotherapy approach for offender population is a type for inmate treatment. CBT is a result of Aaron Beck pioneering work in the 1960s. CBT model is based on the triangle relationships between cognition, emotions and behavior. The cognition is defined as a product of the three levels: cognitive schemas, negative automatic thoughts and dysfunctional thinking or thinking errors. 

The inventory of risk, need and strengths (IORNS), an risk assessment instrument, based on Risk, need and responsivity (RNR) model, was used for selection of (N=27) inmates and CBT treatment pilot program final evaluation, in Macedonian prison Bitola. The evaluation was done by comparing pre and post test measures in (N=12) male inmates, as optimal number for group psychotherapy treatment. According to the RNR model the treatment program needs to be oriented to the inmates needs. Implementing CBT treatment program for group psychotherapy and IORNS as short screening tool in Macedonian prisons was the aim of the project supported by the Council of Europe in this work. The results showed significant lower Procriminal attitudes but higher Aggression because of higher Aggressive behavior in the post measures. Results and instrument can be used in next CBT programs evaluations for better rehabilitation of prison inmates and reducing recidivism.