Comprehensive recommendations on the diagnosis of Turner syndrome (TS) and the care of affected individuals were published in 1994. In the light of recent advances in diagnosis and treatment of TS, an international multidisciplinary workshop was convened in March 2000, in Naples, Italy, in conjunction with the Fifth International Symposium on Turner Syndrome to update these recommendations. The present paper details the outcome from this workshop. The genetics and diagnosis of the syndrome are described, and practical treatment guidelines are presented.