The cost of desalinated water is likely one of the most relevant indicators to characterize and compare desalination with other technical options to supply water for urban, industrial and agricultural purposes, not to mention the social and environmental aspects associated with each option. A first step toward selecting the most appropriate solution to water shortage is to disclose fully and accurately desalination costs associated with each alternative to both government bodies and general public. This is known in economic terms as the full cost. In principle, costs associated with the production of desalinated water are easy to assess. However, it is difficult to compare costs from different facilities in practical terms due to lack of detailed data as well as the lack of a common method for cost estimation. This study aims to present a clear and easy methodology for estimating seawater desalination costs. As a case study, this methodology was applied to seven large-size desalination plants located in the Segura River Basin (Spain). (c) 2012 Elsevier B.V. All rights reserved.