The use of geographical information systems (GISs) in studies of regional integration of renewable energies provides advantages such as speed, amount of information, analysis capacity and others. However, these characteristics make it difficult to link the results to the initial variables, and therefore to validate the GIS. This makes it hard to ascertain the reliability of both the results and their subsequent analysis. To solve these problems, a GIS-based method is proposed with renewable energies for rural electrification structured in three stages, with the aim of finding out the influence of the initial variables on the result. In the first stage, a classic sensitivity analysis of the equivalent electrification cost (LEC) is performed; the second stage involves a spatial sensitivity analysis and the third determines the stability of the results. This methodology has been verified in the application of a GIS in Lorca (Spain). (c) 2005 Elsevier Ltd. All rights reserved.