INTRODUCTION: Children with an anterior mediastinal mass (AMM) need general anaesthesia (GA) or deep sedation for diagnostic procedures more often than adult patients. Anaesthetic management to prevent such complications includes maintenance of spontaneous ventilation (SV) and prebiopsy corticosteroids/radiotherapy. METHODS: We reviewed the medical records of children with AMM who were brought to the operating theatre for diagnostic procedures (prior to chemotherapy) between 2001 and 2013. Our aim was to describe the clinical features, radiological findings and anaesthetic management, as well as determine any association with complications. RESULTS: 25 patients (age range 10 months-14 years) were identified during the study period. Corticosteroid therapy was started before the biopsy for one patient. All 25 patients had GA/sedation. A senior paediatric anaesthesiologist was involved in all procedures. Among 13 high-risk patients, SV was maintained in 11 (84.6%) patients, ketamine was used as the main anaesthetic in 8 (61.5%) patients, 6 (46.2%) patients were in a sitting position and no airway adjunct was used for 7 (53.8%) patients. There were 3 (12.0%) minor complications. CONCLUSION Based on our results, we propose a simplified workflow, wherein airway compression of any degree is considered high risk. For patients with high-risk features, multidisciplinary input should be sought to decide whether the child would be fit for a procedure under GA/sedation or considered unfit for any procedure. Recommendations include the use of less invasive methods, involving experienced anaesthesiologists to plan the anaesthetic technique and maintaining SV.