Despite the fact that laparoscopic surgery has clearly shown benefits in patients with benign ovarian tumor, concerns remain regarding port site metastasis especially when final pathology reveals malignancy. Port site metastasis has been reported in early stages of malignant diseases. However, to our knowledge, there are no reports of port site implantation of malignant cells after laparoscopic surgery for benign disease. We present a 39-year-old woman who had undergone laparoscopic ovarian cystectomy for benign disease, and developed clear cell carcinoma at the site of trocar insertion 11 months after the initial operation. It is possible that the cancer was missed at the time of the initial surgery. Numerous factors have been suggested in the development of port site metastasis including aerosolization of tumor cells, lack of local immune response by the host and unskilled surgical techniques. A careful preoperative evaluation and meticulous laparoscopic maneuvers are the best way to prevent such occurrence.