Six Sigma is regarded as a well-structured methodology for improving the quality of processes and products. It helps achieve the company's strategic goal through the effective use of project-driven approach. As Six Sigma is a project-driven methodology, it is essential to prioritize projects which provide maximum financial benefits to the organization. Generating and prioritizing the critical Six Sigma projects, however, are real challenges in practice. This study aims to develop a novel approach based on a combined ANP and DEMATEL technique to help companies determine critical Six Sigma projects and identify the priority of these projects especially in logistics companies. First of all the Six Sigma project evaluation dimension and components are determined. Decision Making Trial and Evaluation Laboratory (DEMATEL) approach is then applied to construct interrelations among criteria. The weights of criteria are obtained through analytic network process (ANP). An empirical case study from logistics industry is used to explore the effectiveness of the proposed approach. (C) 2010 Elsevier Ltd. All rights reserved.