INTRODUCTION: Very little is known about the characteristics of mesothelial tumours in the paediatric population. In adults with malignant mesothelioma, the pemetrexed-based regimen with cytoreductive surgery (CRS) is a standard of care in limited tumours, but long-term survival is uncommon. MATERIAL AND METHODS: The European Cooperative Study Group on Pediatric Rare Tumors (EXPeRT) retrospectively reviewed children, adolescents and young adults (≤21 year) diagnosed with mesothelial tumours treated between 1987 and 2018. RESULTS: Thirty-three patients were identified, 15 male and 18 female patients. One patient's exposure to asbestos was documented. Primary tumour was mainly in the peritoneum (23 patients). Histology was multicystic mesothelioma of the peritoneum (MCM) (six patients) or malignant mesothelioma (MM) (27 patients). Among MM, the first-line treatment comprised preoperative chemotherapy (14 cases), surgery only (three cases), chemotherapy only (five cases), adjuvant chemotherapy (three cases) or palliative treatment (two cases). The response rate to cisplatin-pemetrexed was 506/12 cases). CRS with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) was performed in 19 patients (upfront in three, after neoadjuvant therapy in 12, or after tumour progression in six patients, including three twice). After a median follow-up of 6.7 years (range, 0-20), five-year overall and event-free survivals were 82.395 confidential interval ((CI), 67.8-99.9) and 45.195 28.4-71.7), respectively. All patients with MCM are alive after surgery (five patients) and CRS-HIPEC (one patient). CONCLUSIONS: Paediatric mesothelioma is exceptional and seems to be different from its adult counterpart with few asbestos exposures, more peritoneal primary, and a better outcome. The cisplatin-pemetrexed regimen showed promising efficacy. Relapses could be salvaged with active therapy including CRS-HIPEC.