Malignant psoas syndrome (MPS) is very rare with poor prognosis, and usually occurs in patients with advanced and recurrent cancer. Authors report herein the case of a 48-year-old female with history of neoadjuvant chemotherapy has been performed before hysterectomy with bilateral adnexectomy and ovariectomy for ovarian adenocarcinoma. She presented 18 months posttreatment with MPS due to a psoas abscess mimicking metastasis confirmed on computed tomography guided fine needle aspiration cytology.