Introduction and importance:Little is known about the rare condition, osseous metaplasia of the uterus, with few cases described worldwide. It is a non-neoplastic transformation in which endometrial stroma is replaced with a mix of bone and cartilage. Occurring commonly after pregnancy, it is thought that the persistence of foetal embryonic remnants contributes to this change. If untreated, osseous metaplasia of the uterus can have a major impact on a woman’s fertility.Case presentation:The authors present a case of a woman with the feeling of a foreign body in the vagina and a long-standing history of secondary infertility of unknown cause. She was found to have osseous metaplasia of the uterus with spontaneous expulsion of the bony fragments from the uterus into the cervical canal, creating the sensation of foreign body in the vagina. She was treated with hysteroscopic resection. Fertility returned 3 months post procedure.Clinical discussion:This case provides a valuable reminder that osseous metaplasia can have a varied clinical presentation and requires a careful history and examination.Conclusion:This case reinforces the importance of a thorough diagnostic assessment in the woman presenting with foreign body in the vagina/cervix and /orsecondary infertility. This rare but important diagnosis can have a lasting impact on a woman’s reproductive health if left untreated.