Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) and paediatric acute-onset neuropsychiatric syndrome (PANS) have been suggested to be a result of a disordered immune response following an infection causing neuropsychiatric symptoms. Although the diagnosis PANDAS/PANS has been controversial, an increasing attention has been paid to the diagnosis, pathophysiology and treatment during the recent years. This review provides an update on knowledge of aetiology, recommended investigations and treatment in children with suspected PANDAS/PANS.