Different currents of opinion have influenced legislation from many countries concerning the psychiatric medical assistance, especially the involuntary admission of mentally ill people. The danger criteria for mandatory admission give rise to a series of ethical dilemmas, from which we mention also the one of danger anticipation. The long term prediction that has as focal point the behavior in different circumstances proved to be hard to evaluate. Manslaughter and suicide among patients with mental disorders in many studies from USA, Europe, Asia, Canada and Australia, in the past 60 years, show that mental illnesses play a major role concerning individual aggression. The objective of this study followed an evaluation of the harm potential in patients admitted involuntarily. Material and method: The studied lot included a number of 202 cases analyzed retrospectively from their charts, patients admitted involuntarily during the period of August 2002 – July 2012 in the University Hospital “Socola” Ia?i. The study is quantitative, retrospective, and the data was taken from the charts of patients admitted involuntarily according to the law of mental health and protection for people with psychiatric disorders, Law 487/2002. Results – The aggressive potential in patients involuntary admitted according to the mental health law was discovered in 46,5 % (selfharm) and 76,7 % (harm of others). Conclusions – The aggression of mentally ill patients is frequently associated with a low degree of disorder awareness and also with coercive admission inside the psychiatric hospital. Among the psychiatric disorders, the aggressive potential is met especially in patients having a diagnosis of “schizophrenia or other mental disorders”.