The present study evaluated the clinical significance of long-term psychoanalytic treatment in four groups of about 60 patients in different phases of treatment (before, during, after, follow-up) with normative comparisons on four symptom questionnaires (SCL-90, BDI-II, STAI, IIP-64) and two personality assessment instruments (MMPI-2, Rorschach-CS). In each group, the proportion of patients with clinically elevated scores was calculated by comparing their scores with clinical and nonclinical reference groups for each instrument. The authors also calculated a combined percentage of clinically elevated scores based on the six instruments as a conservative estimate of improvement to nonclinical levels after long-term psychoanalytic treatment. Compared to pretreatment levels, the authors found a significant decrease in the percentage of clinical cases after treatment. For the personality assessment, these results became even more evident at follow-up. It appears that long-term psychoanalytic treatment was clinically significant for patients with chronic mental disorders. In the discussion, the authors point out that the evaluation of clinical significance at group level should be followed by an examination of individual changes over a longer period of time.