The hydrogeologic exploration using resistivity methods in the Antioquia eastern highlands shows the existence of large groundwater resources both in the aluvial deposits and in the residual soils. The unconfined aquifers are common in the residual soils and in the alluvial deposits, and less common in fractured rocks; confined aquifers are common in the rock basement. Salty aquifers are common both in the alluvial deposits and in the rock basement and deserve attention because of the geological and hydrogeological implications.The groundwater recharge is almost entirely of local origin at the different levels of the highlands. The occurrence of closed depressions known as pseudokarst contributes to the infiltration at the highlands whereas the infiltration at the slopes is almost null.