A total of 50 Transient Electromagnetic (TEM) and 15 Audio-Magnetotelluric (AMT) soundings were carried out in west central part of Portugal over an area of approximately 40 km2 to characterize the geological formations associated with the aquifer of Monte Real. The dimensionality of the AMT profiles was studied using the phase tensor analysis and the AMT data was inverted using a 2D nonlinear conjugate-gradient algorithm. The TEM soundings were inverted using a 1D Lavenberg-Marquardt technique. The TEM results shows that the aquifer is not uniform through the study area; a more resistive zone is evident in the north and northeast of the investigated area where we expect to have higher productivity. Based on the results of this investigation no traces of saltwater intrusion were found for the Monte Real aquifer. Therefore, we assume that the risk of saltwater intrusion is small in the study area.