Pediatric immune disorders encompass an array of disorders with either a systemic or tissue-specific expression, whose phenotype and therapeutic approach often depend on age. More recently, genotypic traits and knowledge of the underlying pathophysiological processes have facilitated a more individualized clinical approach. Molecular characterization in primary immune disorders has provided molecular targets for immunotherapies. In immune-mediated disorders of the CNS, better recognition of pediatric characteristics has enabled earlier diagnosis and treatment initiation. For rhumatismal disorders, like all rare immune disorders, the setting up of multi-centre registers and collaborative studies provide the framework for targeted clinical strategies.