The study focuses on grievance mechanisms in Federal prisons based on unconstitutionality, when physical or psychological prison conditions constitute 'cruel and unusual punishment.' The American Center for Community Justice has established six principles inherent to the system: each grievance must receive a justified reply; the reply must be given within a reasonable and predetermined time period; the grievance must be available for examination by an outside authority independent of the prison administration; inmates and guards participate in the design and application of the grievance procedures; all inmates must have unrestricted access to the grievance procedures; and the mechanism must apply to a wide variety of problems. Prison studies indicate that the LEAA-sponsored procedures are undeniably successful. Although prison violence has not been reduced, measurably the number of inmate lawsuits diminished and inmate attitudes toward the mechanism are very positive. The advantages of the mechanism are numerous and clear: inmates receive a quick and fair hearing of their grievance; the administration is forced to revise outdated or unjust practices as a result of criticism; inmates learn techniques of mediation and negotiation; and prison conditions have been visibly improved as a result of the procedures. Even the guards who were most suspicious of the new system agree that their relations with the inmates have considerably improved. The article concludes that the U.S. grievance mechanism is an essential step in inmate rehabilitation efforts because it diminishes the polarization of opposing factions and gives prisoners increased control over their living conditions. The article includes bibliographical footnotes.