This article examines the linguistic expression of national-cultural concepts in Spanish and Portuguese from comparative-linguistic and linguocultural perspectives. The relevance of the study is grounded in the intrinsic relationship between language and culture, as well as the manifestation of the national worldview through lexical, phraseological, paremiological, and metaphorical units. The study analyzes the linguistic expression of concepts carrying national-cultural significance—such as "home/family," "work," "luck," "friendship," "religion," "Homeland," and "human relationships"—in both Spanish and Portuguese. The research methodology incorporates comparative, descriptive, semantic, linguocultural, conceptual, and contextual analysis techniques. The results indicate that while Spanish and Portuguese share similar conceptual models stemming from common historical and cultural experiences, there are significant differences in their specific linguistic realizations, metaphorical imagery, pragmatic characteristics, and associated national connotations. Paremiological units, in particular, emerge as vital linguistic tools for expressing the national worldview. The findings hold practical significance for comparative linguistics, linguocultural studies, translation studies, and the teaching methodology of Spanish and Portuguese.