Psycho-education is a well-known therapy within a multi-modal therapy concept for patients with schizophrenia and their relatives, as psycho-education is known to reduce relapse and duration of hospital stays. Here, evaluate a new questionnaire to show the gain of knowledge about schizophrenia, especially in combination with psycho-education during a hospital stay. Furthermore, we aim to find out more about the predictors for knowledge gain after participation in 4 to 8 psycho-educational groups. During 5 years (04/2011 to 08/2015) 517 patients and 223 relatives took part in our psycho-educational groups, 136 participants finished the study. In a test theoretical analysis it was shown that the questionnaire “SCHIWI” with 100 items has similar problems as previous questionnaires, but fulfils the criteria “discriminatory power” and “item- complexity” in a reduced version of 22 (was? Erbsen? Cremants?) and can be considered as a valid questionnaire. We could prove again that psycho-education leads to knowledge gain. Furthermore, we found the predictors “frequency of participation”, “basic knowledge” and possibly “relationship to relatives” to be relevant for knowledge gain in patients. Due to the small number of participating relatives we were not able to find secure predictors here, but we found indications that “previous experience with psycho-education”, “subjective knowledge gain” and “education” could be predictors for knowledge gain. This study underlines the importance of psycho-education in the treatment of schizophrenia, but emphasizes the need to find out more about possible predictors in further research.