There is a strong debate regarding the influence of laparoscopic surgery on tumor dissemination and prognosis, especially in ovarian cancer. In murine mammary cancer cell line models, the incidence of surgical metastasis was influenced by the type of surgical trauma. We investigated the influence of surgical trauma on tumor establishment in a synergetic rat ovarian cancer model in 6- to 8-week-old female BD-IX rats using the rat ovarian cancer cell line O-342. The animals underwent i.p. injection of tumor cells, laparoscopy or midline laparotomy with different surgical procedures at the right uterine horn (grasping with a forceps, incision of the uterine horn after coagulation or partial resection of the uterine horn by ligation). Intraperitoneal tumor establishment was then determined 14 days after the surgical procedure, using cancer index scoring (0, no tumor; 1, tumor diameter less than 0.5 cm; 2, between 0.5 and <1.0 cm; 3, between 1.0 and <2.0 cm). No macroscopically visible tumor growth was observed in the uterine horn, which was unaffected by any surgical procedure. Alternatively, for the right uterine horn that underwent grasping by forceps, coagulation or ligation, the cancer index score was found to be 0.2, 2.5 and 3.0, respectively. The present study shows that surgical trauma favors the establishment of tumor lesions in the rat ovarian cancer model.