The results reveal that the trend toward increasing and more focused uses of meta-analyses in criminal justice research should be sustained and expanded. The use of meta-analysis has been increasing over the past two decades on criminal justice-related issues; a number of these may be highlighted as making exceptional contributions to the body of usable knowledge about criminal behavior. The results also suggest the adoption of meta-analysis among criminal justice researchers has been more modest and delayed than in other comparable applied science fields particularly in the medical and health-related disciplines where uses of meta-analysis have increased dramatically. Meta-analysis is an appropriate strategy only for some kinds of questions, such as those resolvable by quantitative empirical data for which an existing body of studies has already been done using fairly commensurable procedures and for which some consensus exists regarding basic definitions and concepts. Data were collected from 176 studies published between 1976 and 2006 using meta-analysis methods on criminal justice topics. Tables, figures, references, and appendix