The human body is equipped with a complex immune system to protect us against germs, cancer cells and foreign objects that cause a health risk. Some children are born with a genetic defect in a part of their immune system. This is called a primary immunodeficiency. These children have a much higher risk of infections and certain other non-infectious complications, such as dysregulation of the immune system and increased risk of cancer. Interstitial lung disease (ILD) is a common non-infectious complication. This is a group of diseases where the tissue of the lungs gets damaged, interfering with the normal functioning of the lungs. Because of the improvements in management of infections, the importance of tackling the non-infectious complications, such as ILD, increases. In order to do this, it is crucial to identify which patients are at risk for ILD and how to diagnose it. Furthermore, patients with this condition can develop severe symptoms and ILD can have a major impact on their life. Because the disease can get much worse over time and can even lead to death, optimised management and follow-up strategies are pivotal. This is the first study that analyses all types of ILD in all paediatric PID patients. The aim of this study was identifying the best ways of screening, diagnosing and following up these PID patients with ILD. Therefore, all relevant studies about ILD were analysed. Based on the results of this study, it can be concluded that all PID patients should be screened for ILD. However, some symptoms and comorbidities were more frequently found in PID patients with ILD compared to PID patients without ILD. This means that clinicians should be more alert for ILD in patients presenting with these features. Furthermore, the risk of developing ILD and the age at which it can be detected, is determined by the type of PID. More adequate screening and close follow-up allows clinicians to treat these patients early and prevent the disease from worsening. Lastly, this study indicated that there is a need for registries including all patients with a PID across different hospitals and countries.