This study discusses a use of DEA-DA (Data Envelopment Analysis-Discriminant Analysis) to assess the corporate value of IT (Information Technology) firms and other manufacturing firms. It is widely known that Tobin's q is a ratio that serves as a measure of corporate value. This study explores a linkage between DEA-DA (as a methodology) and Tobin's q (as a theoretical basis for corporate performance) via the measurement of Altman's Z score (as a financial performance). The Z score provides us with aggregated information regarding financial ratios and other financial measures that investors usually examine in their investment decisions. This study applies the proposed approach to compare between Japanese IT and manufacturing firms. The empirical evidence obtained in this study indicates that R&D (Research and Development) expenditure enhances the corporate value of Japanese IT and manufacturing firms. However, the R&D expenditure of IT firms is important but not essential, compared with other manufacturing firms in Japan. The empirical result is inconsistent with the opinion of many corporate leaders and individuals who are associated with the IT industry. They believe that the R&D expenditure is essential for the Japanese IT industry to maintain its international competitiveness in the global market. In addition to the R&D expenditure, the empirical study indicates that IT leaders need to pay attention to the reduction of an R&D cycle time to enhance their competitiveness because a market cycle time of IT products is less than that of the other manufacturing products. The findings on Japanese IT and manufacturing industries are applicable to other industrial nations. HighlightsÂ? This study discusses a use of DEA-DA to assess the corporate value of IT firms. Â? R&D expenditure enhances the corporate value of Japanese IT and manufacturing firms. Â? R&D expenditure of IT firms is important but not essential, compared with the manufacturing firms in Japan.