Japan's parliament, the Diet, has been in existence for over ninety years, even though it became a truly representative body of the Japanese people only after World War II (to be more precise, after the termination of the American occupation in 1952). In this chapter, after a brief discussion of the Diet under the Meiji Constitution of 1889, the role of the present Diet under the 1947 Constitution and the political functions it performs in the postwar political system will be examined. Recent changes and future prospects for the Diet will also be considered, and wherever possible, Japanese Diet practices will be compared with those of the U.S. Congress.