The key to successful curriculum reform is a broad-based, systematic decision-making process directed by teachers. Common approaches to curriculum development are haphazard and tend to produce superficial change. An approach that gives teachers a personal and professional stake in its results, however, can generate fundamental and lasting reforms. Following introductory passages, a 3-year curriculum development model based on the above concept is outlined step by step. Important features of the model are three teacher-administrator curriculum committees; advice from teachers at large, the community, and professional consultants; pilot testing by specially trained teachers; formative and summative evaluation; and an unspecified mechanism for sustaining the reforms achieved. A case study traces the application of this model in a laboratory school and reports the results achieved to date. A 14-item bibliography is included. (MCG)