Migrant remittances, the transfer of money from foreign migrants to their countries of origin, generate significant financial flows worldwide. Although generally stable, remittance flows are sensitive to economic changes and other crises in migrants’ countries of origin and destination. This paper examines the impact of environmental disasters on remittance flows. It differs from previous literature in that it builds an agent-based simulation of remittance decisions rather than relying on econometric analysis. It first proposes a theoretical model of remittance choice and then applies it to two case studies: Italy as a net remittance sender and Mexico as a net remittance receiver.