The aim of the study was to evaluate reliability, validity and practical applicability of three social functioning scales included in the set of the DSM-IV multiaxial diagnostic instruments. For these purposes 35 schizophrenic patients currently not hospitalized were assessed twice at the interval of 48 hours by two diagnosticians using the three scales under study and 4 alternative tools (of different theoretical assumptions and construction) evaluating various aspects of the patient's functioning and severity of his symptoms. Reliability of the scales under study turned out to be satisfactory. Moreover, obtained evidence indicates a satisfactory, differentiated validity of the SOFAS and GAF scales for the evaluation of extra-familial, socio-interpersonal areas of the patient's functioning, and of the GARF scale – for the assessment of functioning in the family relationships. As regards the two scales characterized by a very similar application and psychometric properties, the assessment using SOFAS seems to be less doubtful than that by means of the GAF scale.