Cuban reform process lags behind the GDP growth reached by the Vietnamese. When comparing the evolution of the different sectors and demand components of GDP, Vietnam has had higher growth rates in all cases, highlighting exports first and investment second. Once the Balance of Payments Constrained Growth model has been estimated, the significant effect of the foreign exchange constraints on growth for both countries is confirmed. However, the Vietnam growth can be explained not only by its export success. International openness, which included the end of the US embargo, and institutional factors also explains the differential of results.