Xanthogranulomatous salpingo-oophoritis (XGSO) is an exceptionally rare entity. Its clinical manifestations and imaging modalities can mimic benign and malignant adnexal diseases, making it difficult to diagnose. Here we report a case of XGSO in a young woman who was operated with suspicion of a borderline ovarian tumour. Preoperative diagnosis of XGSO should be considered to avoid radical surgical treatment, especially in young patients.