Primary squamous cell carcinoma (SCC) associated with ovarian endometriosis is extremely rare and has a poor prognosis due to insufficient information on the optimal postoperative treatment. Here, we describe the response of this tumor to the administration of paclitaxel-carboplatin. A 45-year-old woman diagnosed with stage IIIc primary SCC of the ovary associated with endometriosis underwent optimal surgery followed by six courses of chemotherapy at 3-week intervals with paclitaxel and carboplatin. She tolerated the chemotherapy well and remained without evidence of disease during first-line chemotherapy. Two months later, she was readmitted with recurrence of a pelvic tumor. Although she was treated with chemotherapy (weekly paclitaxel and chemotherapeutic regimen of irinotecan + mitomycin C), the tumor was resistant to second-line and third-line chemotherapy and she died 15 months after surgery. Paclitaxel-carboplatin administration may be an effective treatment for primary SCC of the ovary but further studies are required to investigate it true efficacy in the treatment of this disease.