There is little consistency in policies concerning incentives for offenders to participate in research. With nonoffenders, incentives are routine; in contrast, many jurisdictions and granting agencies prohibit offenders from receiving any external benefits. The reasons for this prohibition are unclear. Consequently, the authors reviewed the ethical and practical concerns with providing incentives to offenders. They conclude that there are no ethical principles that would justify categorically denying incentives for offenders. Research with offenders, however, presents unique practical concerns that need to be considered when determining the magnitude and form of the incentives. In general, the incentives should not be so large as to compel participation of a vulnerable population or to undermine the goals of punishment and deterrence. The authors propose that incentives for offenders should be routinely permitted, provided that they are no larger than the rewards typically available for other socially valued activities (e.g., inmate pay, minimum wage).