The study found little variation among the mean effect sizes of common actuarial or structured risk instruments. These included the Historical, Clinical, and Risk Management Violence Risk Assessment Scheme; Level of Supervision Inventory-Revised; Violence Risk Assessment Guide; Statistical Information on Recidivim scale; and Psychopathy Checklist-Revised. Third-generation instruments, dynamic risk factors, and file review plus interview method had the advantage in predicting violent recidivism. Second-generation instruments, static risk factors, and the use of file review were the strongest predictors of institutional violence. Measures derived from criminologically related theories or research produced larger effect sizes than did those with less content relevance to the theories tested by research. Additional research on existing risk instruments is required to provide more precise point estimates, especially regarding the outcome of institutional violence. In order to be included in the analysis, the primary prediction studies were required to be prospective (i.e., assessment preceded the measurement of outcome); involve adult general offenders or forensic patients; and report sufficient data to calculate an effect size between the prediction measure and violent misconduct or recidivism outcome. The studies included in the meta-analysis pertained almost exclusively to nonsexual offenders and forensic patients with nonsexual violent outcomes. The descriptor, predictor, and outcome data were obtained from studies by using a coding guide created for the current analysis. 5 tables, 4 notes, and 154 references