This paper examines urban schools serving minorities, and begins by arguing that inservice development is the greatest need of the American school system, one that needs many things. The time that a teacher spends in effective inservice activity is more important for the future of pupils than the same amount of time spent with those pupils. Though the impact of formal instruction is as ineffective in an inservice progam as it is in most other settings, a program of formal instruction is an integral part of inservice development. It is held that such a program should be designed to supply instruction in specific skills, attitudes, and knowledge that will complement and reinforce the problem-solving in which staff members are engaged in their daily lives. In discussing the informal inservice climate within the school building and of the school district, the paper emphasizes the role of the principal. It is asserted that no other function gives the superintendent so much power to effect improvements in school districts as the power to appoint and assign school principals. Finally, the paper focuses on the importance of responsible problem-solving at the school building level. Four issues seen as vitally affecting instruction in multiracial and multiethnic school districts are briefly dealt with -- integration, isolation, time, and collective bargaining. (Author/JM)