Hypertrophic osteoarthropathy is a syndrome that includes finger clubbing, periostitis with new subperiosteal bone formation of long bones and arthritis. It is often related to an intrathoracic neoplasms or chronic infections; hence called hypertrophic pulmonary osteoarthropathy. A primary or idiopathic form, also known as Pachydermoperiostosis, also exist. It is commonly seen in children and young adults and has not been found associated with underlying disease. Platelet derived growth factors has been recently recognized to have a key role in the pathogenesis of this disorder. Hypertrophic osteoarthropathy may cause disabling symptoms. Cure of neoplasia may result in regression of the hypertrophic osteoarthropathy.