The intent of this paper is to open for consideration the relationship between metacognition and the promotion of conceptual change within the classroom. This goal is achieved through a brief description of present research by the authors, drawing from the existing literature a summary of what is meant by conceptual change learning, defining the term metacognition and describing the facets included in the definition, a description of the characteristics of a specific learning environment in which metacognition and conceptual change learning occur, and a discussion of the rationale for promoting metacognitive activities within the science classroom. This paper draws on data gathered from three interrelated case studies (M. G. Hennessey, 1991; M. E. Beeth, 1993; and Hennessey, in progress) of students in elementary science at a small midwestern parochial school and provides accounts of students' reflective thinking about science content, students' comments about the relative status of conceptions, and the levels of metacognition that are possible within a classroom setting. Contains 40 references. (DDR)