THE DISCUSSION OPENS WITH A REVIEW OF EDUCATIONAL, POLITICAL, MORAL AND LEGAL RATIONALES FOR DEMOCRATIZING PRISONS. THE EXPERIMENTAL INTRODUCTION OF THE WELFARE LEAGUE CONCEPT BY THOMAS MOTT OSBORNE IN 1913 AND THE IMPLEMENTATION OF THE CONCEPT AT SING SING PRISON IN NEW YORK FROM 1914 TO 1916 ARE DESCRIBED. THE PROJECT INVOLVED THE FORMATION OF AN INMATE COURT AND GRIEVANCE COMMITTEE, WHICH ADJUDICATED INTERNAL DISCIPLINARY OFFENSES AND INMATE COMPLAINTS. THE MUTUAL WELFARE LEAGUE'S EXPERIENCE TYPIFIES THAT OF MANY OTHER EFFORTS TO DEMOCRATIZE PRISONS AND THEREFORE SUGGESTS CERTAIN CONSTRAINTS ACTING AGAINST SUCH REFORM PROGRAMS. AMONG OBSTACLES TO PRISON DEMOCRACIES ARE THE FOLLOWING: THE TENDENCY TOWARD DOMINATION BY INMATE 'ELITES'; FAILURE OF PRISON ADMINISTRATORS AND OTHER PERSONNEL TO SUPPORT DEMOCRATIZATION; CONFLICT BETWEEN CIVIL LAW AND PRISON DEMOCRATIC DECISIONMAKING; PUBLIC SKEPTICISM WITH REGARD TO PRISON DEMOCRACIES; BUREAUCRATIC CONSTRAINTS; AND THE ESSENTIAL POWERLESSNESS OF INMATES. CHANGES NEEDED IF PRISON DEMOCRATIZATION IS TO BE POSSIBLE INCLUDE LEGITIMIZING DEMOCRATIC PARTICIPATION IN TERMS OF THE LEGAL RIGHTS OF INMATES, CREATING PRISONS ARCHITECTURALLY DESIGNED TO ENCOURAGE DEMOCRATIC INTERACTION, EXTENDING FULL CITIZENSHIP TO INMATES, TRANSFORMING PRISONS INTO ECONOMIC ENTITIES IN WHICH INMATES SHARE IN THE PROFITS, INCLUDING STAFF MEMBERS IN THE DEMOCRATIC PROCESS, AND RECOGNIZING THE EXISTENCE OF ETHNIC, POLITICAL, AND OTHER GROUPS IN PRISONS. A BIBLIOGRAPHY IS INCLUDED.