The study aims to identify independent predictors of physical restraint in acute psychiatric patients and to determine the predictive power of a risk assessment model centered on psychopathological dimensions. We included 1552 patients admitted to a psychiatric intensive care unit over a 5-year period. Patients were rated on the Brief Psychiatric Rating Scale (BPRS-E) at admission. Principal axis factoring (PAF) with varimax rotation was performed on BPRS-E items to identify psychopathological factors. Multiple logistic regression analysis was performed. PAF pointed six factors: positive symptoms, negative symptoms, resistance, activation, negative affect, and disorganization. Male sex, younger age, proposal for compulsory admission, severity of symptoms, resistance, activation, and disorganization were identified as independent predictors. Negative symptoms and negative affect were instead protective factors. The BPRS-E factors, when added to other sociodemographic and clinical variables, significantly increased the predictive power of the model. Our findings suggest that a systematic evaluation of the psychopathological dimensions can be usefully included in the early risk assessment of restraint.