The distillation process accounts more than 25% of total process energy consumption in refineries. Therefore the energy improvements of the distillations units are very important for this sector. Six Sigma is a methodology supported by a handful of powerful statistical tools in order to reduce variation through continuous process improvement. This paper proposed the application of Six Sigma methodology for improving energy efficiency in a distillation unit of a naphtha reforming plant. The results reproduce the past energy performance of the unit through multivariate models and show optimal operation mode with an expected savings around 150,000 (sic)/year. Although the process may further improve optimizing the consumption of the reaction unit. (C) 2011 Elsevier B.V. All rights reserved.