BackgroundFibroids are benign tumors of the female reproductive tract originating from the myometrial smooth muscle cells. They are a frequent occurrence in women of childbearing age but their incidence is rare after menopause. In addition, there is a remote possibility of malignant transformation to leiomyosarcoma in less than 1% of cases.Case presentationWe hereby report a case of large fibroid in a postmenopausal Indian female with rapid growth, raising the suspicion of malignant transformation into leiomyosarcoma. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Histopathology report confirmed it to be benign leiomyoma without any evidence of neoplasia.ConclusionSudden enlargement of leiomyoma in postmenopausal women should not be ignored due to possible malignant transformation and is to be dealt immediately with hysterectomy followed by histopathology.