Autism spectrum disorder (ASD) is a neurodevelopmental disorder (NDD) that affects about 78 million people worldwide. Its prevalence and degree of impact on individuals and families place it among disorders of global importance. ASD resulted in 4.31 million (95% UI 2.82-6.23) global Disability-Adjusted Life Years (DALYs) in 2019, equivalent to 0.2% (0.1-0.2) of DALYs and contributed to 3.4% (2.7-4.3) of DALYs for the aggregate of mental disorders. Evidence shows that early and tailored intervention limits the impact of symptomatology and improves the quality of life of people with ASD and other NDDs and their families. Early identification of clinical signs (red flags) is the first step to facilitating prompt referral for an assessment and diagnosis. In many cases, features of ASD/NDDs manifest early in development (first 6-12 months), although the specificity of these signs is still unclear. Three infants' populations are at higher risk for developing ASD/NDDs compared to the general population: siblings of children diagnosed with ASD (18.7%), preterms, and Small for Gestational Age (SGA). In preterm infants, the prevalence of ASD has been estimated as 7% (95% IC, 4-9) and ADHD is diagnosed twice as often (OR: 1.6; 95% CI: 1.3-1.8). Moreover, the risk for developing ASD in SGA has been estimated as 1.17 (95% CI, 1.09-1.24). Setting up a system to monitor infant neurodevelopmental trajectories through a specific experimental and clinical protocol will enable strategic preventive actions. Early detection of ASD/NDDs requires the mainstreaming of child development monitoring into Child Psychiatry Units (CPUs) and Neonatal Intensive Care Units (NICUs) follow-up programs of at-risk infants. Since 2010, the ISS coordinates the Italian Network for early detection of Autism Spectrum Disorders (NIDA Network), actually involving 45 NICUs and 148 CPUs implicated in the diagnosis and treatment of infants at risk for ASD/NDDs in all Italian Regions. Within the NIDA Network, the ISS implemented a clinical protocol for monitoring at-risk infants for ASD/NDDs in the NICUs follow-up and CPUs. However, the implementation of the protocol in the clinical routine practice requires human resources with specific competences in child psychiatry test scoring and motor/vocal/social behavioral analysis. The BABY@NET project will add to 6-to-36 months well-established clinical NIDA protocol, the experimental data collection and analysis of behavioral and neurophysiological/biological features (vocal, motor, social, EEG, genetic/epigenetic, metabolomic, and secretome), in the first 12 months of age, found altered in ASD/NDDs children. The existing IT platform will be improved for collecting research data, audios/videos, tests and providing the telehealth support to those NICUs and CPUs that suffer from shortage of human resources and competences in testing and video scoring of high risk infants. Through statistical analysis of clinical, behavioral, and neurophysiological/biological endpoints, it is possible to identify early risk signals that can significantly anticipate ASD/NDDs diagnoses in at-risk and general populations. The clinical/experimental protocol combined with the digital infrastructure (e-health) will be implemented in NICUs and CPUs throughout the National Health Service (NHS) ensuring the population of at-risk newborns a specialized assessment, the neurodevelopmental surveillance and activation of personalized prevention interventions.