Popular Speech in Managua’s Markets offers a rich and empirical exploration of the Nicaraguan popular lexicon as used in the bustling commercial spaces of Managua’s markets, where language becomes both a tool of trade and a marker of cultural identity. Grounded in extensive fieldwork, the research involved 621 interviews conducted across ten capital markets and three departmental locations, covering thirteen specific sections of commerce—from groceries and footwear to butcher shops and local eateries. The investigation not only identifies and organizes the lexical units used in these environments but also traces their semantic, phonological, and syntactic behaviors, highlighting the expressive nuances of Nicaragua’s everyday speech. By cross-referencing these terms with eleven dictionaries and relevant texts, the study verifies established meanings or, in cases of absence, provides contextual definitions that underscore the creative and adaptive nature of popular language. It further includes a curated list of Americanisms prevalent in Nicaragua, situating this localized lexicon within a broader linguistic framework. The result is a compelling documentation of how the oral tradition and market dynamics coalesce to sustain a vibrant and evolving linguistic ecosystem. These markets, functioning as both economic and social hubs, become vital arenas where language reflects social stratification, regional influences, and linguistic innovation, ultimately offering insights into how identity, commerce, and communication intertwine in the vernacular practices of a nation.