Benign multicystic peritoneal mesothelioma is an uncommon lesion arising from the peritoneal mesothelium. It is asymptomatic or presents with unspecific symptoms. Imaging techniques may reveal it, however the final diagnosis can only be made by histopathology. Surgery is the only effective treatment considering its high recurrence rate. We report a 19 years old male with Crohn’s disease. Due to persistent abdominal pain, an abdominal magnetic resonance imaging was performed, showing a complex cystic mass in the lower abdomen. The patient underwent surgery and the lesion was completely resected. The pathological study reported a benign multicystic peritoneal mesothelioma.Benign multicystic peritoneal mesothelioma is an uncommon lesion arising from the peritoneal mesothelium. It is asymptomatic or presents with unspecific symptoms. Imaging techniques may reveal it, however the final diagnosis can only be made by histopathology. Surgery is the only effective treatment considering its high recurrence rate. We report a 19 years old male with Crohn’s disease. Due to persistent abdominal pain, an abdominal magnetic resonance imaging was performed, showing a complex cystic mass in the lower abdomen. The patient underwent surgery and the lesion was completely resected. The pathological study reported a benign multicystic peritoneal mesothelioma.