Background: It's widely assumed that patients rehabilitate better in community than in inpatient facilities. Moreover deinstitutionalization saves health care costs. However, deinstitutionalization may reduce patients' compliance and entail substantial risks since patients with schizophrenia have increased risk of becoming violent and/or committing suicide. OBJECTIVES: Investigate the relation of risk of harming self and/or others and symptoms in schizophrenia to improve prevention and diagnosis of patients who present a risk to society. METHODS: The association between Positive and Negative Symptom Scale (PANSS) and risk of harming self/others as measured by Camberwell Assessment of Need (CAN) score was assessed using logistic regression (N=171). Standard statistical tests were applied to evaluate the significance of relationship between total PANSS, sub-scores (negative, positive, general psychopathology) and all 30 items, and risk of harming self/others. Receiver Operating Characteristic (ROC)-curves were used to assess discrimination. Calibration was quantified by the slope of the prognostic index. Model parameters were internally validated by bootstrapping. RESULTS: PANSS is significantly associated with risk of harming self/others with an area under the curve (AUC) of ROC of 0.763. Patients with total PANSS of 70 and 80 have a 6.8% (95% CI 3.6%-12.4%) and 9.8% (95% CI 5.1%-17.8%) risk of harming self and/or others respectively. The models including PANSS negative sub-score or PANSS blunted affect item had an AUC of ROC of 0.784 and 0.786 respectively for patients' risk of harming self and/or others. Discussion: Reducing (negative) symptoms, especially blunted affect, may reduce patient's risk of harming others and/or themselves. Therefore the importance of preventing deterioration in a patient's condition as measured by PANSS is not only beneficial to the patient but also to society. Given the difficulties in this patient population about maintaining treatment compliance, it may be worthwhile to allocate funds aimed at reducing symptoms directly or indirectly by improving compliance.