Approximately 3% of newborn infants present with minor or major defects for which the pediatrician's advice is required. The diagnosis approach of a dysmorphic syndrome at birth relies upon a systematic four-step evaluations including: 1) family history; 2) information on the perinatal history; 3) complete physical examination with careful description of the morphological anomalies; 4) oriented imaging, laboratory and/or cytogenetic investigations. In many cases the regrouping of the different information will lead to the diagnosis of a precise malformation syndrome. However the etiological diagnosis may also be difficult at birth and will necessitate a regular follow up in order to take into account the evolution of the defects and the occurrence of additional clinical signs.