The current study reveals a positive correlation between vocabulary size and reading comprehension.It would also be beneficial to spend extra time teaching students academic vocabulary to acquire the most frequently used academic words since knowing those words will improve the coverage of academic texts.EFL teachers at Saudi universities should introduce academic vocabulary to students to enhance their lexical knowledge.EFL teachers could provide separate vocabulary classes focusing on academic vocabulary and the most frequent 2000 words.In addition, teachers and students should be aware of some major aspects of learning vocabulary such as the definitions of words, synonyms, antonyms, word collocations, and semantic and pragmatic characteristics.The use of various methods of teaching are highly recommended for assisting EFL learners in enlarging their lexical knowledge.Instructors should increase their awareness of the usage of lexis in the classroom.