Abstract: Training in Peritoneal Surface Oncology has traditionally been through self-effort. There is a growing demand for experts in this field given its expansion, and therefore the need for structured education and training has become urgent. The European School of Peritoneal Surface Oncology (ESPSO) was created in 2014 as a joint effort of the European Society of Surgical Oncology (ESSO) and the Peritoneal Surface Oncology Group International (PSOGI). We describe its training program and mentorship-based methodology, leading to the European Certification in Peritoneal Surface Oncology. From 2014 to July 14^th 2021, 42 surgeons graduated from this program. Most of them were from European countries, but there were non-European graduates as well, giving this initiative a global outreach. Currently, 35 candidates are enrolled in European and non-European institutions. Given the success of the current program an expansion is underway, with the incorporation of new faculty members and newly planned educational activities. The ESPSO has succeeded in establishing a structured mentorship-based Training Program leading to a Certification, that has gained prestige and demand, counting on numerous graduates and candidates around the globe. The next level in this training project is warranted. This article is to describe the training program.