Neonatal screening for Hyperphenylalaninemia (HPA) is compulsory by law in Italy since 05/02/1992. Italy's incidence of newborns affected by ant form of HPA is equal to 1:3,494 live births, with 1:8.681 requiring specific treatment (Annual Technical Report 2010-SIMMESN). The following data were obtained by a questionnaire sent to all 16 Italian Centers involved in PKU management. The total number of patients is 3527 (44% males, 56% females) plus 471 late diagnosis, and 2474 of them are actually in follow up. Adult patients (more than 18 years of age) are 904, with 649 females in childbearing age, 83 pregnancy are reported, 54 of them with normal fetal/neonatal outcome. 33% are classic PKU, while 42,6% are HPA on free diet. In use strategies for PKU treatment: 88% dietary treatment, 7% BH4 and 5% Large Neutral Amino Acids (LNAA). 47 patients with a diagnosis of BH4 deficiency are reported. Since 2010 a National PKU Registry has been established, supported by SIMMESN, with 817 patients actually included. In Italy, in the last 40 years, centers' collaboration, experiences' interchange, research and studies collaborative commitment, Italy's engagement in EU project has guaranteed and guarantee the best clinical management for PKU patients, beyond rare disease.