The term 'autoinflammatory disease' encompasses an enlarging group of inflammatory disorders defined as Mendelian genetic diseases of the innate immune system. This group is growing considering the fact that diseases sharing strong similarities with this core group can be defined as autoinflammatory. The core group consists now of six disorders also known as hereditary recurrent fever syndromes. Thez most common is familial Mediterranean fever, an autosomal recessive disease affecting mainly populations of Mediterranean ancestry. All these six diseases are characterised by inflammatory attacks both at the clinical and at the biological level. The diagnosis of each of these diseases relies first on clinical features and second on genetic testing, which is guided by the clinical results. Deciphering the role of interleukin-1 in the regulation of the inflammatory response through the inflammasome represents a major advance in the knowledge of the mechanisms of these diseases with, as a main consequence, treatment with interleukin-1 inhibitors. (C) 2009 Elsevier Ltd. All rights reserved.