Research confirms that combining texts and illustrations in teaching materials, enhances learners’ achievements. However, many educators, authors and textbooks’ analysts may not share this claim. For them, the idea that the textbooks, in general and the textbook illustrations in particular have a positive/negative impact on EFL learners’ outcomes has not been thoroughly examined. Therefore, this study provides empirical evidence regarding the side-effects of the use of textbooks’ illustrations and their influence on EFL learners’ attitudes from a hidden curriculum perspective. More specifically, this study is designed to determine if gender is portrayed in Spotlight on English1, a textbook of first year Middle School, in a neutral and impartial way. The sample of the study consists then of the above mentioned textbook currently in use and a number of pupils estimated as approximately 23 boys and 23 girls. To collect data, the textbook illustrations where male and female characters are shown, are content analyzed. To know how women and men are depicted, a set of well-defined variables are put forward. They include productive versus reproductive occupations, sport activities, and frequency of appearances. The results show that males’ illustrations outnumber the females’ picture representations. In addition, women were portrayed more often, in stereotypical activities that reinforce the traditional image of them in society such as being a teacher, secretary, type-writer, and top-model. Men were depicted in more outdoor, adventurous, and skillful activities such as being a doctor, journalist, veterinarian, and actor, among other occupations. Physical education and sport games are also depicted as a male-domain. It is also important to stress that, such a preconceived allocation of roles, attitudes and actions reduces the girls’ future prospects in their lives as well as boys’ attitudes and knowledge about people and how do they relate to each other DOI: 10.5901/mjss.2015.v6n5p435