The aim of this paper is to present comparison of clinical diagnoses and SCAN (Schedules for Clinical Assessment in Neuropsychiatry, version 2.1) diagnoses of patients treated in day care and inpatients wards. SCAN was translated at Medical University of Wrocław according to WHO permission. It is a part of multicenter study evaluating effectiveness of treatment in conventional psychiatric hospital and day hospital for acute psychiatric patients. Clinical diagnoses were made using ICD-10 classification system. Till now 56 patients were examined, 15 men and 39 women in age from 21 to 65 years old, median age 45 years old. Among them 31 patients were treated in day care wards, and 25 patients were treated in inpatients wards. During standard medical procedure diagnoses of 25 patients were classified into the block F2, and 19 patients into the block F3 of ICD-10 classification. Schizophrenia were diagnosed in 16 patients of, 19 patients had diagnosis of depressive disorder, and 21--of other mental disorders. Clinical diagnoses were in most of the cases single one; there were only 6 cases with double (comorbid) diagnoses. SCAN diagnoses were multiple, ranged from 1 to 12 (median 3) for one patient. Many concomitant SCAN diagnoses referred to tobacco use, sleep disorders, and somatoform disorders. Cohen's kappa coefficient for the block F2 was 0.78, for schizophrenia--0.62, for the block F3--0.42, and for depression--0.36. Results showed low agreement between clinical and SCAN diagnoses, particularly for mood disorders. The explanations of such discrepancies could be: no strict compliance with rules of ICD-10 by clinicians and avoidance of comorbid diagnoses by clinicians or errors in the SCAN coding algorithms. Further analyses are needed to characterize more precisely the sources of discrepancies.