The global use of the English language in various international contexts complicates the role of culture in teaching English as an international language. Drawing on a well-known framework of cultural representation consisting of four categories of "products," "practices," "perspectives," and "persons," this study focused on a content analysis of three ESL grammar textbooks. The findings indicated that contrary to the expectation regarding the cultural neutrality of grammar textbooks, the analyzed textbooks were, to a large extent, predominated by the "practice" aspect of culture which comprises the behavioral patterns of a certain society involving information about daily life and prominent customs. With regard to the scope of foreign cultures manifested in these textbooks, a lack of balance was evident. This can be traced to the fact that compared to international cultures, the cultures of English-speaking countries occupy a larger space in these textbooks and hence has caused little room for the international cultures the targeted textbooks. It is suggested that learners receive more help in developing their intercultural competencies and promoting effective communication with people coming from different backgrounds through using English as an international language. This can be made possible if materials writers pay further attention to the role of international culture.