Many studies of social anxiety disorder (SAD) have been conducted because diagnostic criteria are defined as social phobia in DSM-III in the West. In Japan, several studies have examined pathological conditions similar to SAD, known as taijin-kyofu (TK). This highly remarkable disorder involves a convincing fear of giving another person discomfort from one's physical faults (e.g. feeling that neighboring people detect an unpleasant smell from one's body, "jikoshu-kyofu", or feeling that neighboring people feel unpleasant because of one's appearance,"shukei-kyofu") termed "convinced subtype of TK" (c-TK; also known as offensive subtype of TK). In DSM-5, the definitions of feeling rejection and offense of others are added to a fear of humiliating or embarrassing oneself. Moreover, TK is a sufficient criterion for SAD. However, it is confusing that body dysmorphic disorder is not in category of somatoform disorders but in that of obsessive-compulsive disorder and related disorders and that the Japanese terms of "jikoshu-kyofu" and "shubo-kyofu" are categorized as other specified obsessive-compulsive disorder and related disorders. The efficacy and tolerability of selective serotonin reuptake inhibitors (SSRIs) for the treatment of SAD has been reported in many controlled studies. Recently, SSRIs are regarded as first line pharmacotherapy for SAD. Cognitive behavioral therapy is also effective for SAD treatment. High rates of co-occurring SAD and other psychiatric disorders can be found in clinical samples and in the general population. Additional research must be conducted for these patients and for the management of treatment-refractory SAD patients.