Introduction: Smooth muscle tumor of uncertain malignant potential (STUMP) still represents a medical and surgical challenge, being rare and hard to diagnose. Normally STUMP consists in a multitude of uterine tumors that do not meet the current histologic criteria for a specific malignant or benign tumor. Clinical, imagistic and laboratory investigations seem to only raise the presumptive diagnosis in these cases, the diagnosis being confirmed during histological examination of the post hysterectomy/myomectomy specimen. Case report: We present the case of a 50-year-old female patient who was examined for the first time for pelvic pain and sensation of increased pressure in the lower abdomen in June 2020. A gynecology consultation was performed, during which a large uterine mass was felt on vaginal digital examination combined with pelvic palpation. Further pelvic ultrasound examination revealed a voluminous tumor of the left ovary. Then, a magnetic resonance imaging was performed, which showed a large pelvi-abdominal tumor of probable ovarian origin with a mixt tissue type and cystic structure, the presence of pathological abdominal and pelvic lymph nodes, ascites with a suspicion of peritoneal carcinomatosis. The patient was referred to a tertiary center and the multidisciplinary team recommended surgical treatment. A total hysterectomy with bilateral oophorectomy and stadial lymphadenectomy was performed. After surgery, the patient had a favorable evolution and was discharged five days after the intervention in a good health condition. Macroscopic and histological examinations of the biopsy pieces showed morphological aspects of uterine smooth muscles tumors with uncertain malignancy potential/STUMP and multiple uterine leiomyomas. Discussion:Due to the rarity of these tumors, the scientific literature needs to be constantly updated in order to help physicians to correctly identify and treat this pathology. It is highly recommended to identify tumors with a high malignancy potential, so that the follow up will be sufficient to discover and treat recurrences before they become life-threatening. Conclusion:Smooth muscle tumor of uncertain malignant potential remains a difficult diagnosis due to uncertainty between malignancy and benign features. Treatment approaches are difficult in these cases and must always be in accordance with the patients' desire to maintain their reproductive functions and fertility. Recurrence of STUMP has been reported, therefore a close follow up of these patients must always be performed.