Since the 2000s, MERCOSUR, the Southern Common Market of Argentina, Brazil, Paraguay, and Uruguay, established different mechanisms supporting the mobility and protection of intraregional migrants, as in the case of the MERCOSUR Residence Agreement. However, the current socio-political collapse of the post-Hugo Chávez regime in Venezuela represented a major challenge to this approach as millions of Venezuelans emigrated to neighbouring countries in the region. In this context, MERCOSUR has faced important pressures to steer governance arrangements that respond to the migration of Venezuelans based on a human rights approach. Against this backdrop, our paper looks into the role of MERCOSUR in the regional governance by asking how and why has (not) the regional organisation reconciled top-down (i.e. nation-states) and bottom-up (i.e. civil society and sub-national governments) approaches to immigrant reception? By looking into Mercosur, the paper contributes to assessing whether and how the regional level works as an adequate regulatory mechanism where states and constellations of non-state actors and networks cooperate in the response to common regional challenges derived from human mobility. Our question is highly relevant as concerted and multilateral responses to migration based on a human rights approach have been, until the recent approval of the 2018 Global Compacts on Migration and Refugees, elusive at a global scale.