The present work makes a comparison between the two most used environmental sustainability indices of nations: "ecological footprint" and "environmental sustainability index", with two emergy ratios (renewability and emergy sustainability index). All of them are gaining space within the scientific community and government officials. Despite the efforts for obtaining an index that adequately represents the sustainability of a region, according to the result of this research, nowadays there is not yet a completely satisfactory index. We consider that all of them need to be improved, but the results point out the possibility of obtaining one better index of sustainability through the junction of ecological footprint with renewability emergy index. © 2007 Elsevier B.V. All rights reserved.