This paper traces the interaction between the policies of the Boston Teachers Union and the desegregation of the Boston Public Schools. A case study analysis illustrates how the process of pursuing the social objective of desegregation affects, and is affected by, a number of key aspects of the labor management relationship. These aspects include: (1) recruitment and hiring policies; (2) layoff and transfer policies; (3) the role of seniority versus affirmative action; (4) internal union politics; and (5) the relationships between the union, the courts, the school department, and various community groups. The issue of job security is examined in respect to the entire desegregation process. (Author/APM)