We examine the phenomenology, epidemiology, and aetiology of specific phobias in this brief review. In general terms, a specific phobia exists when fear of a specific object or situation is exaggerated, cannot be reasoned away, results in avoidance of the feared object or situation, persists over time, and is not age-specific. Specific phobias occur in about 5% of children and in approximately 15% of children referred for anxiety-related problems. Most of these children are comorbid with other disorders. We suggest that specific phobias are multiply determined and over-determined. Genetic influences, temperamental predispositions, parental psychopathology, parenting practices, and individual conditioning histories converge to occasion the development and maintenance of childhood phobias. Inasmuch as any one specific phobia is acquired and maintained through such complex processes, we further conclude that treatment approaches will need to address these multiple dimensions before evidence-based treatments can be fully realised.