Prognostic assessments by forensic psychiatrists and psychologists are of high relevance to many judicial decisions such as granting of graduated enforcement schemes, release from prison and other correctional institutions or for decisions concerning the ordering of preventive measures. Currently two risk assessment methods are mainly being discussed: the clinical method and the actuarial risk assessment. The clinical method focuses on the precise analysis of the individual case. It uses so-called criteria catalogues for the structured evaluation of aspects relevant to prognosis. The assessment of several evaluation levels according to such criteria catalogues represents an improvement of earlier lists of criteria and is currently considered 'state of the art' in German-speaking countries. Actuarial instruments on the other hand are based on statistical group comparisons in regard to sociodemographic and criminological variables. Different studies showed these instruments to be superior to assessments by clinical psychiatrists, which is why they are the preferred method in Anglo-Saxon countries. However, the prognostic validity of prognostic assessments in general is frequently being doubted even though the individual risk dispositions can be determined in many instances with sufficient precision. From the year 2000 to 2003 69 persons considered to be dangerous were being psychiatrically/psychologically assessed in the context of the Zurich Brief Assessment Project. Brief risk assessments are focal risk appraisals for decisions which need to be made on a short-term basis, e.g. if violent acts are being threatened and/or in regard to releases from remand detention. Aside from assessing the offending or re-offending risk, also recommendations were given in the context of the risk assessments on how to lower that risk. The assessees were mostly not detained for a long period of time after the assessment which made it possible to evaluate the quality of these brief risk assessments using the rate of renewed offending as criterion. Re-offending was evaluated both on the basis of criminal records as well as information from preliminary proceedings. For 65% (n = 37) of the 56 persons detained at the time of the assessment a release from remand detention was recommended. For more than two thirds of the assessees (78%; n = 54) the release was connected to a condition. For 71% (n = 49) of the assessees a therapeutic measure was recommended, second most recommendation was to appoint a case manager (35%; n = 23). For 16% (n = 11) abstinence from psychotropic substances, for 12% (n = 8) the prescription of medicine and for 11% (n = 7) a ban to carry firearms was being recommended. After three years only five persons had re-offended with a violent offence. They were limited violent acts (mostly assaults) in which nobody was heavily injured. These results can be seen as supporting the assumption that a combination of professional risk assessment and case-specific recommendations on risk-reducing measures can lower the offending and re-offending rate especially concerning grave violent acts.