This article outlines the use of concept maps as a tool for science curriculum development and discusses the changes that occur in the teacher's view of the curriculum with successive revisions of the maps. Although we have used concept mapping in curriculum development with teachers from grades 4–8, we describe in detail the maps created by sixth-grade teachers. We analyzed the maps using three criteria: hierarchical structure, progressive differentiation, and integrative reconciliation. Changes made to the maps during the revision process, including additions and deletions, show increased clarification of both the concepts to be learned and the connections between them. Consecutive map revisions show the development of a cohesive conceptual grade-six science curriculum. The use of concept maps can help science teachers develop science curriculum that is hierarchically arranged, integrated, and conceptually driven.