Aim. Many authors consider motivation as an important factor influencing psychotherapy outcome. There is a discussion, whether motivation is a stable construct or a dynamic process. Material and methods. The purpose of the study was to investigate the dynamics of motivation and the relationship between motivation and clinical improvement during the inpatient integrative psychotherapy. The data was collected from 274 patients. The Questionnaire of Motivation, measuring: helplessness, activity, sense of wrongness, sense of threat, was a key tool. Measures for assessing the clinical and personality change were also applied: Symptoms Check List, Adjective Check List, Sense of Coherence. They were distributed at: the placement on the waiting list, the admission to the department and at the end of the 10-weeks therapy. Results. Motivation showed the strongest influence on symptoms' level at the time of admission. The personality variables had stronger influence at the end of the treatment. All factors of motivation changed both during the waiting list period and the therapy. Helplessness, sense of wrongness and threat showed a steady decline. The level of activity rose significantly during the treatment, parallel to the clinical improvement. The helplessness motivational factor was predominant at both pre-treatment occasions. Conclusions. Assessment of motivation should be recognized as a standard procedure at the different stages of therapy. The most efficient way of strengthening the internal motivation is active participation of the patient in his/her therapy process.