This book attempts to assess the effectiveness of the textbook, “Visa to the World” designed for Moroccan High School Students. The evaluation is carried out on the basis of seven main criteria: the physical appearance and format of the textbook, the accompanying materials, the content and the topics, the exercises and the activities, cultural presentation, the four skills and the language methods. On the whole, the main conclusion that can be drawn from the results of this study is that teachers’ perceptions about the particular textbook are negative in general. Indeed, both quantitative and qualitative results of this investigation enable us to deduce some implications, which will provide guidance to the textbook writers and evaluators. One of the most significant implications that can be drawn from this research is the necessity to carry out a detailed needs analysis before designing a textbook. Thus, both teachers and students’ needs should be assessed and taken into consideration in preparing and evaluating a textbook.