This chapter covers the manufacturing technologies used by U.S. and Japanese aerospace companies in the fabrication of aerospace products made from polymer composites. This discussion of composites manufacturing technologies is presented in the context of the aerospace industry because the aerospace industry has been and remains at the cutting edge of this technology. The emphasis will be on the methods used to reduce the per-pound cost of finished composite structures. The chapter begins with a brief discussion of the history of composites manufacturing, particularly in the aerospace sector. The remainder of the chapter is a detailed and comparative discussion of the current status of relevant composites manufacturing technologies in the U.S. and Japan, followed by discussion of possible future trends in the technology, particularly for demanding advanced aerospace applications.