Abstract Background VEGF and Dll4/Notch pathways play important roles in tumor angiogenesis. The purpose of this study is to investigate the expression of these two pathway molecules in ovarian cancer and their possible relationships in carcinogenesis. Methods Twenty-eight specimens of human ovarian carcinoma, 18 of benign ovarian and 20 of healthy ovarian tissues were subjected to immunohistochemical analysis for VEGF, VEGFR1, and VEGFR2, Dll4, Notch1, and Notch3 expression. Microvessel density (MVD) was evaluated by counting the number of CD34-stained microvessels in each pathologic specimen. Results The expression of VEGF, VEGFR1, Dll4, Notch1, or Notch3 in ovarian tumor tissues was higher than that in normal ovary tissues as well as that in benign ovarian tumor tissues (P<0.05). In the tumor tissues, Dll4 was positively correlated with VEGFR1 expression and Notch1 was positively associated with VEGFR2 and MVD. Moreover, VEGFR2 expression was positively associated with ascites and distant metastasis (R=0.401, P=0.034). Conclusions Dll4 represents a potential biomarker and therapeutic target for ovarian angiogenesis. VEGFR2 is significantly related to ovarian metastasis and invasion. Therefore testing the key molecules of these two pathways expression may have some diagnostic and prognostic value for ovarian cancer.