This paper is an empirical study aimed at examining the extent to which Six Sigma activities influence the enhancement of corporate competitiveness. Although this research topic has been frequently introduced through case studies in the relevant literature, no statistical empirical research results have been reported to date. Therefore, in this study, to address this research topic, 161 survey questionnaires were collected from Six Sigma-related personnel working at large Korean corporations that had already been implementing Six Sigma activities, and the results of statistical analysis are presented. The development of survey items related to Six Sigma activities drew upon the TQM research literature, and the empirical analysis was conducted using a structural equation model. The analysis results empirically confirmed that Six Sigma activities have a positive impact on process innovation and quality improvement in firms, and consequently exert a substantial influence on corporate competitiveness.