Hidden curriculum indicates that some of the outcomes of schooling are unintentional, frequently negative outcomes. The purpose of this study is to examine the hidden curriculum in the sixth-grade English textbooks. The major research question was stated as “What are the cultural, authoritative, and gender hidden curricula in English textbooks?” The method of content analysis was adopted in order to explore the hidden curriculum within the eight sixth-grade English textbooks. The findings included: (1) gender difference was found in the working class and housekeeping; for example, males tend to take professional jobs, whereas females do not; (2) instant food like hamburgers was presented in the English textbooks in a constant way, instead of other healthful American food; and (3) the high social-economical job and life style were introduced all through the eight textbook contents, without attention to low-level ones. However, English textbooks also place the emphasis on Taiwanese cultural activities, including various activities about the Moon Festival and the Chinese New Year.