Background: Disorders of immunity are poorly recognised in some rare multisystem genetic con-ditions. We aim to describe syndromic features and immunological defects in children with syn-dromic primary immunodeficiencies (sPIDs). Methods: This is a retrospective descriptive study of children aged 0-18 years with sPIDs under the care of the paediatric immunology service at the Bristol Royal Hospital for Children, United Kingdom from January 2006 to September 2021. Results: sPIDs were identified in 36 patients. Genetic diagnoses which are not commonly associ-ated with PIDs and not included in the International Union of Immunological Societies classifica-tion were present in 7/36 (19%): Trisomy 22, Arboleda-Tham syndrome, 2p16.3 deletion syn-drome, supernumerary ring chromosome 20 syndrome, Myhre syndrome, Noonan syndrome, trichothiodystrophy/Cockayne syndrome complex. Recurrent and/or severe infections were the commonest clinical features (n=33, 92%). Approximately half had combined immunodeficiency or antibody deficiency. Commonest extra-immunological manifestations include dysmorphism (72%), disorders of nervous (78%), musculoskeletal (69%), haematology/lymphatic (58%), and gastrointestinal, hepatic/pancreatic (58%) systems. Conclusions: Patients with sPIDs often have multiorgan involvement and some are non-immunologically mediated. There should be low threshold to clinically assess and investi-gate for disorders of immunity in any patients with syndromic features especially when they pre-sent with recurrent/severe/opportunistic infections, features of immune dysregulation, autoin-flammation or lymphoproliferation.