IN 1973 INMATES FILED A CLASS ACTION LAW SUIT AGAINST PUERTO RICO'S CORRECTIONS SYSTEM FOR ALLEGED VIOLATIONS OF DUE PROCESS IN PRISON DISCIPLINARY PROCEEDINGS. THE CONSENT DECREE WHICH RESULTED FROM WEEKS OF NEGOTIATION PROVIDED A MANUAL OF REGULATIONS TO ENSURE A FAIR HEARING BEFORE AN INMATE COULD BE PUNISHED. SUCH PROCEDURAL SAFEGUARDS ARE NECESSARY TO PREVENT PRISONER ABUSE, AND THE COURTS HAVE BECOME THE MAJOR TOOL USED BY PRISONERS TO PROTECT THEIR RIGHTS. CORRECTIONAL AND LEGAL LITERATURE CONCERNING PRISON DISCIPLINARY PROCEDURES IS REVIEWED. THE STUDY EXAMINED FOUR INSTITUTIONS: A PENAL CAMP, A JAIL, A FACILITY FOR YOUNG ADULT OFFENDERS, AND A WOMEN'S PRISON. IN EACH CASE CONDUCT REPORTS PRIOR TO AND AFTER THE 1973 REGULATIONS AND OTHER RECORDS WERE ANALYZED. DISCIPLINARY HEARINGS WERE OBSERVED, AND INTERVIEWS WERE CONDUCTED WITH INMATES, PERSONNEL, HIGH RANKING OFFICERS IN THE CORRECTIONAL SYSTEM, HEARING OFFICERS, AND COUNSELS. THE STUDY FOUND THAT INSTITUTIONS WERE GENERALLY NOT COMPLYING WITH THE REGULATIONS AND THAT INMATES WERE BEING ARBITRARILY AND SEVERELY PUNISHED BY PRISON OFFICIALS. THIS FACT WAS ATTRIBUTED TO THE LACK OF SUPPORT TO THE LACK OF SUPPORT GIVEN TO THE REGULATIONS BY THE CORRECTIONS DEPARTMENT WHICH CONSEQUENTLY ENCOURAGED RESISTANCE BY PRISON OFFICIALS. RECOMMENDATIONS ARE PROPOSED TO CHANGE THE NEGATIVE ATTITUDE TOWARD THE REGULATIONS AND PROVIDE RESOURCES TO IMPLEMENT THE HEARING PROCESS. TABLES ACCOMPANY THE CHAPTERS ON METHODOLOGY AND FINDINGS. THE APPENDIXES CONTAIN THE TEXT OF REGULATIONS GOVERNING THE DISCIPLINARY PROCEDURES IN PENAL INSTITUTIONS OF THE COMMONWEALTH OF PUERTO RICO, DETAILS OF OBSERVED HEARINGS, AND THE QUESTIONNAIRE USED IN INTERVIEWS. AN EXTENSIVE BIBLIOGRAPHY OF BOOKS, ARTICLES AND PUBLIC DOCUMENTS IS PROVIDED. (MJM)