Contemporary levels of international migration in less-developed countries are raising new and important questions regarding the consequences of immigration for human welfare and well-being. However, there is little systematic cross-national evidence of how international migration affects human development levels in migrant-receiving countries in the less-developed world. This paper addresses this gap in the literature by assessing the impact of cumulative international migration flows on the human development index, a composite measure of aggregate well-being. A series of panel models are estimated using a sample of less-developed countries for the period, 1970-2005. The results indicate that higher levels of international migration are associated with lower scores on the human development index, net of controls, but that the effect of international migration is relatively small.