Abstract The purpose of this study was to conduct a corpus-based evaluation of English for Ethiopia textbooks for grades 9-12, as well as receptive vocabulary knowledge of students who used the textbooks. The four textbooks were evaluated in terms of lexical coverage, vocabulary frequency, vocabulary range, and reading threshold vocabulary knowledge. The study also looked into whether students' vocabulary knowledge was adequate for independent reading. This research project's methodology is corpus-based research methodology. Using computer software, the method involved compiling and analyzing the textbook corpus. BNC high frequency word list and Academic Word list, as well as vocabulary profiling software, were used for its analysis framework. The Vocabulary Size Test was used to assess students' receptive vocabulary knowledge. The test was given to 107 students in grade 12 at Bahir Dar Preparatory and Secondary School. The study's findings revealed that the textbooks have a variety of weaknesses in terms of vocabulary. The major disadvantages include having too many words than necessary, including and excluding vocabulary items at random, inappropriate variation in vocabulary within textbooks, failing to incorporate lexical frequency band standards, and having a low number of common vocabularies among textbooks. The findings also revealed that the textbooks contained a high number of low-frequency words, 47 percent of the general vocabulary, and 60 percent of the reading sections vocabulary consists of low-frequency words with a frequency of less than five. The reading vocabulary threshold was knowledge of 3000– 4000-word families for textbooks in general and 4000–7000-word families for reading sections at 95 and 98 percent text coverage, respectively. In terms of AWL presentation, the findings revealed that academic words are well presented; 498 of 570 (87 percent) academic words are in textbooks, and the majority of academic words are presented frequently. Furthermore, the results of the vocabulary size test revealed that students in the study did not achieve the receptive vocabulary knowledge required for the majority of reading scenarios. Students' receptive vocabulary size was 3096-word families, which is below the independent reading level. Based on the findings, it was determined that the textbook requires some changes aimed at limiting the vocabulary used and easing the difficulty of reading sections vocabulary. Finally, it was suggested that teachers and students be informed about the textbooks' flaws and use vocabulary research findings and tools that can be used to compensate for the textbooks' flaws.