Cognitive behaviour therapy (CBT) is widely regarded as an effective treatment for social anxiety disorder (SAD) in Europe and North America. The theoretical orientations underlying CBT models and treatment interventions developed in Western cultures were typically constrained by Western conceptualizations of SAD. This case study reports on the use of CBT for Japanese SAD, demonstrating the successful implementation of cognitive techniques grounded in the Clark & Wells model. The patient was a Japanese female with excessively high standards for workplace social performance. Therapy mainly comprised case formulation, behavioural experiments, and opinion surveying based on the Clark & Wells model. These techniques allowed the patient to reduce the strength of maladaptive cognitions and lower her excessively high standards for social performance. CBT treatment using the Clark & Wells model was effective and suitable for Japanese SAD, at least in the present case. We also discuss the cross-cultural differences of SAD and adaptation of CBT.