: In this article, the psychometric properties of the Forensic Inpatient Observation Scale (FIOS) were examined. This instrument was developed to observe behavioral functioning of forensic psychiatric patients. Up till now, it has only been used among adult forensic psychiatric patients and this is the first study in which the FIOS is used with youngsters. | Psychometric evaluation of the Forensic Inpatient Observation Scale (FIOS) in youngsters with a judicial measure