The recurrence of respiratory tract infections is a common problem in paediatric practice. Parental concerns around recurrent respiratory infections (RRTI) contribute significally towards doctor visits. This a a surprising lack of evidence, guidelines and appropriate ICD 10 cording for RRTI. Many of the children who present with RRTI are immunologically normal children but it is important to recognise the features of a possible immune deficit or other serious underlying disorder. The evaluation children who present with RRTI requires close attention to the history and clinical findings in order to differentiate those who warrant more extensive investigations from those who need reassurance directed toward their concerned parents. PID may be responsible for around 10% of RRTI in children. More than 50% of these are due to antibody defects and the majority can be diagnosed and treated effectively. The question that arises is when to start more extensive investigations and when to accept that this child is otherwise healthy. The purpose of this review is to assist the clinician with a diagnostic approach to differentiate the "normal" child from the child with a more serious underlying aetiology of RRTI, necessitating investigation.