A two part examination of the evidence concerning one possible basis for the poor mathematical performance of United States students, the content of the textbooks used in their classes, is presented. The results of a detailed analysis of Japanese and U.S. mathematics textbooks for grades 1 through 12 are reported. Two international studies (1964 and 1981) and the Dallas Times Herald study are used as the basis for comparison. The first part of the research study contains a discussion of elementary school children in Japan and the United States, similarities and differences in Japanese and U.S. elementary school textbooks, and the differences between the two sets of textbooks when concepts and skills are introduced. The study concludes that material contained in the Japanese elementary school textbooks is somewhat more advanced than in the U.S. texts and concepts and skills are likely to appear earlier in Japanese textbooks. The second part of the study discusses an analysis of secondary school textbooks in the United States and Japan. The paper concludes that U.S. textbooks may form an obstacle to the learning of mathematics because they are long, wordy, and repetitive. Two extensive appendices (over 70% of the document) contain exhaustive summaries of the contents of the Japanese and U.S. elementary and secondary mathematics textbooks chosen for the study, arranged by concept and skill. (RSL)