The quest for finding the best way to teach L2 vocabulary in EFL classes has been adopted by many researchers for so long, yet the various aspects of vocabulary knowledge keep the search ongoing. One of the main factors in determining the effectiveness of the way in which L2 English vocabulary is taught is the textbook. Textbooks can be very diverse in that they can pursue different methods and attend more or less to various aspects of vocabulary knowledge and learning. English textbooks at high school level in Iran have been rewritten recently, which has made salient changes in the way vocabulary was taught in high school EFL classes. This study explores Iranian EFL teachers’ attitudes toward these changes to find out the effectiveness of the new textbooks in L2 vocabulary teaching and whether they have made an improvement. For this aim, structured interview questions were designed by the researcher. Seven high school EFL teachers, including both males and females, who had at least 5 years of experience were interviewed. Structural content analysis of the interview transcripts was used to find relevant themes. The results suggest that in general, Iranian teachers have a positive attitude toward the new way of L2 vocabulary teaching applied in high school textbooks and consider it as an improvement. Implications are made for teachers and material developers for further application.