This review aims to present social anxiety disorder from a developmental psychopathological perspective. Evolutionary theories share the view that social anxiety might be adaptive in specific contexts, and suggest several mechanisms of dysfunction (adaptive trade-off , mismatch, individual differences). The aetiology of social anxiety disorder is characterized by a complex interplay of genetic and environmental factors including gene-environment interactions,correlations and epigenetic mechanisms. Although the main diagnostic criteria of social anxiety disorder are the same throughout the lifespan, developmental characteristics alter its presentation. In children, behavioural symptoms are common. We can view refusal of speech as a specific manifestation of avoidant behaviour related to young age. Therefore, some researchers suggest that selective mutism is an age-specific subtype of the disorder. Even though the majority of researchers agree that behavioural inhibition is an age-specific temperamental risk factor of social anxiety disorder, it might also be viewed as an early, subclinical form of the disorder. In adolescence, as part of the normal development, there is a temporary increase of social anxiety. In this age group, however, there is also an increase in the prevalence of socialanxiety disorder. Adult-onset social anxiety disorder is rare. In adults, social anxiety disorder has to be diff erentiated from avoidant personality disorder. Social anxiety disorder is characterized by strong homotypic continuity, but evidence for a heterotypic continuity is also available,especially with other anxiety disorders and major depression, probably due to shared genetic factors. The developmental psychopathological approach of social anxiety - developmental paths, age-specific characteristics, etc. - may contribute to an early recognition of the disorder and facilitate more effective therapeutic interventions.