Objective: The purpose of this study was to determine risk factors for trocar implantation metastasis after diagnostic laparoscopy in patients with primary or recurrent advanced ovarian cancer. Study Design: Eighty-three women with primary advanced ovarian cancer and 21 women with recurrent ovarian cancer undergoing a laparoscopy for a tissue diagnosis and for assessment of operability were included in the study. The occurrence of implantation metastasis at the trocar incision scars was analyzed according to clinicopathologic characteristics. Results: A recurrence developed at the trocar site in 7 (58%) of 12 patients undergoing a laparoscopy in which only the skin was closed at the end of the procedure and in 2 (2%) of 92 patients undergoing a laparoscopy with closure of all layers (odds ratio, 63; 95% confidence interval, 10.3-385; P < .001). The International Federation of Gynecology and Obstetrics stage at initial presentation, tumor histologic type, tumor differentiation, maximal tumor diameter at the time of diagnosis, estimated weight of the metastatic tumor, residual tumor after cytoreductive surgery, surgical characteristics, and type of chemotherapy were well balanced among both groups. Patients with implantation metastasis had significantly more ascites (median, 700 mL vs 300 mL; P = .032) and a longer interval between the start of platinum-based chemotherapy or cytoreductive surgery (median, 6 days vs 17 days; P < .01) compared with patients without abdominal wall recurrence. A palpable abdominal wall metastasis developed in none of the patients undergoing a laparoscopy with closure of all layers of the abdomen followed by cytoreductive surgery or chemotherapy within 1 week after the laparoscopy. Kaplan-Meier survival analysis showed that patients with abdominal wall implantation metastasis had a survival rate similar to that of the other patients. Conclusions: Laparoscopy with careful closure of the peritoneum, rectus sheath, and skin followed by chemotherapy or cytoreductive surgery with excision of the trocar trajectories within 1 week is safe in patients with disseminated ovarian cancer. (Am J Obstet Gynecol 1999;181:536-41.)