Using a dynamic spatial framework, this paper investigates how foreign direct investment (FDI), foreign aid and remittances impact the economic growth of 53 African and 34 Latin American and Caribbean countries. Previous growth studies examine how one factor or two of these factors impacts economic growth, which results in biased estimation because of the omitted variable(s). Separate estimation shows foreign aid and FDI affects economic growth in Africa, but when we control for all three factors, only FDI affects African economic growth. For Latin America and the Caribbean, foreign aid and remittances affect growth when estimated separately, while remittances affect growth when they are estimated simultaneously. Finally, both regions' results confirm spatial interdependence is important in explaining economic growth, as growth in one country depends on the growth of its neighboring countries.