Some anticipatory anxiety is expected on specific occasions such as giving a speech. However, some individuals have an excessive fear of such situations when they are under scrutiny, believing that their performance will cause them embarrassment or humiliation, frequently leading to deliberate avoidance of these situations. This disabling condition has been termed social anxiety disorder. Social anxiety disorder is common, with a lifetime prevalence of 2% to 5%, but is probably underreported. The sufferer often avoids seeking assistance, leading to comorbid mental disorders, greater disability, and an increased risk of suicide. Consequently, a high burden is placed on the patient's caregivers and on society. The diagnosis of social anxiety disorder is aided by the patient's history together with DSM-IV criteria. Research into the neurobiology of social anxiety disorder suggests a dysfunction of postsynaptic serotonin receptors and a hypersensitivity to challenge with caffeine, CO2, and pentagastrin. Neuroimaging studies suggest a dysfunction of the striatal presynaptic dopamine transporter in social anxiety disorder. Clear guidelines for the management of social anxiety disorder, including both pharmacotherapy and psychotherapy, are yet to be established. Selective serotonin reuptake inhibitors (SSRIs) show the most promise for the future, while cognitive-behavioral therapy may also be helpful. In the meantime, physicians should treat social anxiety disorder promptly and aggressively.