This paper reviews studies of volunteer programs in criminal justice. The use of volunteers has become increasingly popular. Evaluation of this innovative approach to offenders has been inadequate. Most studies are technically flawed in that they lack effective control groups and do not control for bias. All the studies, methodologically weak or otherwise, indicate that volunteer programs are effective. The studies show lower recidivism rates, diversion of the offender from unacceptable behavior patterns, and participant satisfaction. Most studies do not place sufficient emphasis on offender adjustment. Effective measurement criteria need to be developed for such programs. The development of a broad data base involving a variety of programs will enable researchers to assess volunteers' effectiveness with greater accuracy. The paper includes a 10-item bibliography.