The neonatal behavioral observation is an important source of medical information in three domains: 1) assessment of development which can be done with the Assessment of Preterm Infant Behavior, 2) assessment of pain with the analysis of facial expression using validated pain scales such as the Neonatal Facial Coding System, 3) assessment of brain injuries with the Quality Assessment of General Movements. Such a behavioral observation of the newborn using validated tools is a useful complement of the neuro-imaging techniques.