Effective English for Specific Purposes (ESP) training depends on coursebooks for relevant and genuine vocabulary. Corpus-based analysis is a reliable empirical technique for lexical evaluation in ESP coursebook assessment, as shown in this research. Thus, this quantitative corpus-based research focused on (1) the most common general English lexical items and (2) domain-specific vocabulary in tertiary English for Tourism coursebooks. The study was a quantitative corpus-based one that included 3,423,973 words from all primary reading materials, dialogues, and exercises in the 2020-2022 English for Tourism coursebooks. Using corpus linguistics methods, WordSmith Tools discovered and evaluated lexical frequency lists and domain-specific keywords. This study found that, although generic high-frequency terms are important, tourism-related language dominates the materials' specialized vocabulary. Generally, high-frequency lexical terms, essential for language development, were detected. The most common domain-specific vocabulary, mostly nouns, was tourism terminology, including "guest," "hotel," "room," "travel," and "tourism." This study provided actual lexical data to help curriculum developers and teachers plan, choose, and adjust tourist education resources. This aligns with real-world language needs and improves ESP instruction.