Recent migratory flows transiting through Central America have led to unprecedented institutional and humanitarian responses across the sub-region. Between 2015 and 2016, the small Central American countries and Costa Rica in particular experienced at least two major “migration waves,” triggered by thousands of “extraregional migrants” in transit from Cuba, Haiti, and many countries from Asia and Africa who became stranded for months in Central America. The article examines how these recent and unusual migratory flows led to novel state responses, including the use of disaster risk management principles and operational mechanisms. Based on empirical data from Costa Rica, the article explores how the concept and notion of complex unbounded emergency (risk) may be appropriate in understanding the practical implications of this new migratory reality in terms of disaster risk reduction and management. It aims to shed new insights on the complexities of extraregional migratory flows, which are likely to continue into the foreseeable future.