This study aims to verify the application of aerial gammaray spectometry to localize mafic ultramafic rocks.The data are collected over Angico's farm, Curaçá County, northern Bahia, Brazil.The region is largely known as copper ore producer from Curaçá's Valley, and by Delgado and Souza (1975) presents numerous mafic and ultramafic rock placed along the the valley.We have observed that the identification is possible only over areas where the underground bodies are relatively shallow and have reasonable dimensions.