A total of 1487 eleventh grade students in Leipzig (Germany) and Sendai (Japan) were given a test of basic concepts and operations in high school mathematics and a questionnaire involving beliefs, attitudes, and practices related to mathematics, their own abilities, and their psychological adjustment. Large differences were found between the two countries in the students’ performance. The lower scores of the German students are attributed to three major areas of difference. Compared to Japanese students, German students were less critical of themselves and their academic ability, held lower standards for their performance, and were less likely to attribute excellence in performance to studying. Students in both countries expressed few indications of maladjustment. When differences were found the indices of maladjustment were more common among German than among Japanese students. Boys obtained higher scores on the mathematics test than girls, were more likely to spend more time studying mathematics, and placed more importance on going to college than did girls. The poor performance of the German students appears to be attributable to the same kinds of beliefs and attitudes as those found in prior studies of US students, who also have received low scores on tests of mathematics achievement.