THE OBSERVATIONS WERE MADE DURING FIELD WORK CONDUCTED IN AN EVALUATION OF COEDUCATIONAL FACILITIES. THE IMPACT OF THESE FACILITIES IS DISCUSSED IN TERMS OF INSTITUTIONAL CHANGE, HETEROSEXUAL RELATIONS, AND OTHER RELATIONAL EFFECTS. THE INTRODUCTION OF OPPOSITE-SEX INMATES TO PREVIOUSLY SINGLE-SEX INSTITUTIONS AND THE OPENING OF NEW COED FACILITIES HAVE PRODUCED CERTAIN CHANGES IN THE REALITIES OF INSTITUTIONAL LIFE. THERE HAS BEEN A REDUCTION IN THE AVAILABILITY FOR FEMALE OFFENDERS OF THE OPTION TO BE INCARCERATED WITH INMATES OF THE SAME SEX. A CORRESPONDING REDUCTION IN OPTIONS HAS NOT TAKEN PLACE FOR MALES. THE PROCESS OF INTEGRATION HAS BEEN ACCOMPANIED BY CERTAIN HOUSING SHIFTS AND SECURITY MODIFICATIONS. AVAILABILITY OF TRADITIONAL WOMEN'S PROGRAMS AND OPPORTUNITIES FOR WOMEN TO HOLD JOBS IN PRISON HAVE BEEN DECREASED ONLY OCCASIONALLY. THE MAJOR ISSUES RELATED TO HETEROSEXUAL RELATIONS IN COED INSTITUTIONS -- NORMALIZATION TO 'STREET' BEHAVIOR AND EXTENT OF BISEXUAL ACTIVITY -- REQUIRE SYSTEMATIC INVESTIGATION. IN THE FIELD STUDY, THE EXTENT TO WHICH A SHIFT TOWARD HETEROSEXUAL RELATIONS WAS OBSERVED APPEARED TO DEPEND ON THE ACTUAL LEVEL OF INTEGRATION. THERE IS LITTLE EVIDENCE THAT THE 'RETURN TO STREET BEHAVIOR' SYNDROME IS WIDESPREAD IN COED INSTITUTIONS. A PATTERN OF 'RELATING TO THE OPPOSITE SEX BY DAY AND THE SAME SEX BY NIGHT' HAS BEEN OBSERVED AMONG SOME WOMEN IN INTEGRATED INSTITUTIONS, PARTICULARLY WHERE THE LEVEL OF INTEGRATION IS LOW OR DECLINING. THESE WOMEN CONTINUE THEIR HOMOSEXUAL RELATIONSHIPS FOR SUPPORT AND ENGAGE IN HETEROSEXUAL RELATIONS FOR FINANCIAL PURPOSES. OTHER MAJOR RELATIONAL EFFECTS OF INTEGRATION INVOLVE POWER STRUGGLES, FAMILY PATTERNS, AND ROLE STRUCTURE.