Tropical mountain regions contain the main headwaters of important rivers in Central America. We selected 2 contrasting catchments located in a mountainous region to evaluate the precision of daily flow estimates based on the Hydrological Land Use Change (HYLUC) and Nedbør-Afstrømnings Model (NAM) hydrological models. A second objective was to simulate the impact of expected climate change for the year 2050 on stream flows and seasonal distribution of rainfall.