Introduction: To assess the prognostic value of lymphovascular space invasion (LVSI) in epithelial ovarian carcinoma. Methods: We reexamined single representative hematoxylin and eosin-stained sections of 66 patients with epithelial ovarian carcinoma to identify LVSI. A 4-grade system was used to classify LVSI: Absent (no LVSI), mild (1-2 foci of LVSI), moderate (3Y8 foci of LVSI), and severe (≥9 foci of LVSI). We investigated the possible associations between the grade of LVSI and clinicopathologic factors. Results: Lymphovascular space invasion was present in 36 patients (54.5%) and absent in 30 (45.5%). Statistical analysis indicated that LVSI was significantly associated with advanced clinical stage, poor histological grade, and lymph node metastasis. Follow-up studies indicated that the disease-free survival time for patients without LVSI was significantly longer than that for patients with moderate LVSI (P = 0.01) and severe LVSI (P = 0.001). The overall survival (OS) time for patients with moderate or severe LVSI was significantly shorter than that for patients with mild or no LVSI. The grade of LVSI was found to be significantly associated with OS (P = 0.004). The grade of LVSI showed poor correlation with disease-free survival and OS. Copyright © 2010 by IGCS and ESGO.