English for Academic Purposes (EAP) and English for Specific Purposes (ESP) are developing branches of English as a Foreign Language (EFL) instruction in Iran. These branches have a marginal status in the tertiary education, and the Ministry of Science, Research, and Technology’s high commission offers no clear guidance for selecting and developing basic academic instructional materials related to the linguistic or communicative standards expected by teachers (Mazdayasna & Tahririan, 2008). This paper tries to evaluate an ESP textbook written for BSc students of physics entitled, ‘English for the students of physics’, which is prepared by the Center for Studying and Compiling University Books in Humanities (SAMT). The present research was based on qualitative and quantitative research techniques and included two steps. First, internal, external and overall evaluation of the book was carried out based on McDonough & Shaw (1993) model. While conducting the external evaluation of the book, the intended audience, the proficiency level, the context of use, the language, the author's views on language and methodology, the inclusion of a vocabulary list/index, visual features, and the cultural aspects were examined. The internal evaluation included the presentation of the skills, grading and sequencing, discourse skills, listening section, the representation of different learning styles. And in overall evaluation, general suitability of the textbook was assessed. In the second step, six teachers each responded to a 22-item textbook evaluation questionnaire to express their perceptions concerning various aspects of the textbooks. The results revealed the extent of appropriateness of the textbook used by BSc students of physics. Suggestions are offered for the future revision and/or designing the textbooks.