["Population and Development Review, EarlyView. ", "\nAbstract\nThreat evasion—the need to escape imminent threats to safety and survival—is a major driver of international migration. Demographic research on threat‐evasive migration, however, remains scant, owing to a longstanding dearth of systematic data on migrants in need of international protection (MNP). To that end, we leveraged respondent‐driven sampling (RDS), a methodology designed to access “hidden” populations in the absence of a reliable sampling frame, to recruit and survey MNP in Costa Rica—one of the top receivers of MNP worldwide. Here, we illustrate the utility of telephonic RDS to yield systematically diverse samples of MNP that encompass a broad range of national origins, immigration statuses, premigration violence exposures, and socioeconomic conditions. We show that compared with convenience sampling, RDS yields a more diverse sample that better captures the characteristics of the underlying population and that neither past violence exposure nor current socioeconomic precarity impedes survey recruitment. Finally, we highlight the empirical and theoretical importance of sampling across legal categories and widening the demographic lens beyond asylum‐seekers alone.\n"]