This study aims to systematically identify research trends and the overall landscape of Vietnamese lexical studies conducted in Korea over the past 25 years. To this end, 56 KCI-indexed journal articles on Vietnamese vocabulary published between 2000 and 2025 were selected and analyzed in terms of annual publication trends and thematic distribution. In addition, keyword frequency analysis and LDA-based topic modeling were employed to quantitatively uncover latent thematic structures within the dataset. The results indicate that Vietnamese lexical studies in Korea have primarily focused on Sino-Vietnamese vocabulary and polysemy from semantic perspectives, while recent studies have increasingly adopted pragmatic approaches, cognitive linguistic perspectives, and data-driven methodologies. Topic modeling identified four major research clusters: (1) pragmatic semantic analysis and pedagogical applications centered on address and reference terms; (2) the establishment of lexical categories and the construction of lexical databases as research infrastructure; (3) contrastive semantic studies on meaning differentiation and lexical correspondences of homographic Sino-character words within the Sinosphere; and (4) studies on figurative meaning extension focusing on proverbs, idioms, body-part terms, and basic verbs. By quantitatively structuring accumulated research outputs and presenting a comprehensive overview of the field, this study offers an integrated understanding of Vietnamese lexical studies in Korea and suggests future research directions, including the expansion of lexical pedagogy research and further investigation into the internal lexical system of Vietnamese.