Research has demonstrated the effectiveness of both individual and group cognitive behavior therapy (CBT) programs for social anxiety disorder (SAD) with patients in many countries. The present preliminary study reports the effectiveness of individual CBT for Japanese patients with SAD. Fifteen outpatients diagnosed with SAD completed an individual CBT program of six 50-min sessions with several components, including cognitive restructuring to modify cost and probability bias, repeated speech exposure, and homework about idiosyncratic anxiety-provoking situations. The results show that SAD symptoms improved after completion of the program. Large effect sizes were found for cognitive factors of SAD. In addition, repeated speech exposure was highly effective for improving the self-perception of subjective anxiety. The present findings suggest that an individual CBT program can be effective for reducing SAD symptoms with Japanese patients.