An International Comparison on industrial platinum resistance thermometers (PRTs) among the National Metrology Institutes (NMIs) of Spain, Mexico and the Andean Countries (Bolivia, Colombia, Ecuador, Peru and Venezuela) began in 2004 and was successfully completed in 2005. Two PRTs were circulated (hand-carried) and compared from −40 °C up to 250 °C. The Centro Espanol de Metrologia (Spanish NMI), CEM, was the pilot laboratory and the Centro Nacional de Metrologia (Mexican NMI), CENAM, was the co-pilot laboratory. This report presents the results of this comparison and provides detailed information of the measurements performed by the participating laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).