To ensure the sustainable use of water and adequate protection of the aquifer is necessary to know the areas most vulnerable to contamination and establish programs specific inspection and monitoring. The objective of this research was to model the vulnerability of aquifers in the county of Aracatu using methods DRASTIC, GOD and MAIA, in order to compare the results obtained. This paper presents the results of mapping the vulnerability of aquifers in the county of Aracatu, located in the southwestern state of Bahia in semi-arid region, where the population lives with recurrent droughts and water shortages of good quality. The region is located in south-central part of São Francisco Craton, where crystalline rocks outcrop of Archean and Proterozoic age with a variety of structural alignments, predominantly in the direction NW-SE and NE-SW, parallel to the main fracture systems that aquifer system is in a fissure of great importance for rural supply, especially in dry periods, when groundwater is the only alternative to supplying the population. The vulnerability indices were calculated and modeled using the software Surfer 8. 0. The vulnerability indices were correlated with each other and the concentrations of nitrate, using maps and charts to evaluate the behavior of each.