This article examines the usage of the directional verbs with "out" and "in" in Vietnamese idioms and proverbs. It draws on the book "Vietnamese Idioms and Proverbs Dictionary" by Vu et.al (1992) to conduct a descriptive and analytical study based on structure analysis, lexical meaning analysis, and modification and replacement methods. The verbs with "out" and "in" act as either central verbs or auxiliary verbs in Vietnamese idioms and proverbs. Additionally, the article explores the usage of these directional verbs from a cognitive linguistics perspective, taking into account Vietnamese perception of language and culture. Finally, it proposes a number of ideas for teaching Vietnamese idioms and proverbs containing directional verbs with "out" and "in" in a cognitive linguistics context to foreign learners.