Rationally selected Comprehensive System (CS; Exner, , 1993Exner, , 2003 Rorschach variables and suitability for psychodynamic psychotherapy were investigated in four studies with different designs. The participants comprised three clinical samples (n = 52, 25, and 69) of patients applying for and/or selected for dynamic psychotherapy. With few exceptions the CS variables were the same in the studies, and in all the studies the Rorschach was independent of clinical ratings/assessments and/or selection of patients for treatment. The first study dealt with the relation between 17 rationally selected CS variables and suitability for psychotherapy as represented by ratings of Dynamic Capacity and Ego Strength and by selection of therapy applicants for psychotherapy. The second and third studies concerned CS score differences between groups of patients differing in suitability for dynamic psychotherapy. In the second study, differences for CS variables were predicted for three groups of dynamic psychotherapy patients with mixed diagnoses. In the third study, CS score differences between two groups, differing in suitability but similar in comprising personality disordered patients, were predicted and tested. In the fourth study, correlations were predicted between 18 pre-therapy CS variables and patient post-therapy satisfaction with therapy and also with therapist post-therapy ratings of their patients' suitability for dynamic therapy.For the four studies taken together, positive results were obtained for EA, FC, the D Score, Blends, Zf, F%, MQo, and AG. The results for m, SumT, WSUM6, X-%, S, and FrrF were negative, whereas the results for YFY, FD, COP, and PER were too weak to permit interpretation.The main limitation of the research in this thesis is the lack of psychometric data concerning the clinical ratings whereas the strength is the ecological validity. The results are positive for some of the CS variables selected, mainly concerning control and cognition but also touching upon emotional integration and interpersonal forcefulness. The usefulness of the CS in psychotherapy assessment may be enhanced if only those CS variables that are found valid for the purpose are used and general personality descriptions are avoided.