The purpose of this publication is to present descriptions of all of the current uses of research reactors. The necessary criteria to enable an application to be performed are outlined for each application. In many cases, the minimum requirements as well as the desirable requirements are given. This publication will be of particular benefit to those seeking to increase the utilization of their facilities and to those thinking of installing a new research reactor or modifying an existing facility. The order in which the applications are presented progresses from those that are possible on any reactor, such as training, to those that require higher power and more specialized reactors with expensive experimental facilities, such as neutron capture therapy. In addition, a simplified research reactor capability matrix is developed and presented in Appendix I, which at a glance enables the determination of the applications that may be appropriate for a particular power level reactor. The IAEA officer responsible for this publication was B. Dodd of the Division of Physical and Chemical Sciences.