Chronic recurrent abdominal pain is a common manifestation in children. Functional abdominal pain is the most common cause of chronic abdominal pain and can be diagnosed properly by the physician without the requirement of specific evaluation when there are no alarm symptoms or signs. Functional abdominal pain is categorized as functional dyspepsia, irritable bowel syndrome, functional abdominal pain, abdominal migraine, and aerophagia, according to the Rome II criteria for pediatric functional gastrointestinal disorders. New concepts on the pathogenesis of functional abdominal pain include brain-gut interaction, visceral hypersensitivity, gastrointestinal dysmotility, inflammation, autonomic dysfunction, genetic predisposition, and triggering factors including psycho-social stress.