The purpose of the thesis was to produce a compact guidance for the employees of Soite adult psychiatry outpatient care about guiding patients and treatment process for Dialectical Behavioral Therapy (DBT). The request for the guidance to be made as a thesis came from the supervisor of the adult psychiatry outpatient care department. The DBT treatment model has been used in Soite since 2019. DBT is a therapeutic treatment model designed especially for treating unstable personality disorders. This treatment has been proven to be helpful even for patients with difficulties in emotional regulation and interaction skills. The goal of the treatment model is to learn how to regulate emotional reactions and act under difficult feelings. DBT is very intensive and structured care which includes both group intervention and individual intervention. The care is carried out with as equal cooperation from both the patient and the employee as possible. The thesis was conducted in cooperation with the staff working according to DBT at Soite adult psychiatry outpatient care. Theoretical information has been searched from the databases, literature, and studies of this area of expert expertise. The goal for compiling the guidance was to clarify the process and practices of treatment in the DBT model at Soite adult psychiatry outpatient care. The goal was to also make the patient more committed to the DBT treatment model and to help employees inform and direct the patients into treatment as well as clarify the treatment process. The usability of the new guidance was evaluated using Webropol survey. The survey got less answers than anticipated so the results might not be fully reliable. However, the results suggest that new guidance may be helpful. The main objective of the project was to compile a guide for the employees. This objective was reached, and the client accepted the guidance to be implemented. The guidance has been shared for usage by employees of Soite adult psychiatry outpatient care and the client has been given rights to make changes to the guide in case the DBT treatment model is updated.