Background: Lymphovascular invasion (LVI) of malignant tumor is regarded as an initial state of metastasis, including the lymph nodes, and therefore may be a prognostic factor in many malignancies. However, in gastric cancer, according to the current Japanese guidelines, LVI is not clinically useful information, except for in predicting the curability of endoscopic resection, and its clinicopathological characteristics and biological behavior remain unclear. The present study explored the histopathological significance of LVI in gastric cancer and clarified its correlation with the prognosis. Methods: From January 2000 to December 2013, a total of 2090 cases of gastric cancer undergoing radical gastrectomy were enrolled in this study. The correlation of LVI and other histopathological factors with the prognosis was evaluated. Lymphatic vessel invasion (ly) and venous invasion (v) were diagnosed followed the current Japanese classification. LVI positivity (LVIP) and LVI negativity (LVIN) were defined as the presence of lymphatic vessel and/or venous invasion and the absence of LVI, respectively. Results: LVIP was noted in 894 cases (42.8%). The age (p < 0.001), depth of tumor invasion (pT) (p < 0.001), lymph node metastasis (pN) (p < 0.001), and maximum tumor size (p < 0.001) were significantly correlated with the presence of LVI. A multivariate analysis showed that pT (p < 0.001), pN (p < 0.001), and LVI (p = 0.03) were independent risk factors for the prognosis of all patients. On analyzing the significance of every T factor and N factor for the overall survival of LVIP and LVIN cases, no significant difference was recognized in the prognosis among all pT1 patients and pT2-4 patients without nodal metastasis. However, in pT2-4 patients with nodal metastasis, a significant difference was revealed, and the 5-year overall survival rates in LVIP cases were lower than those in LVIN (60.9% [95% confidence interval: 56.3-65.3] vs. 76.7% [95% confidence interval 65.2-84.8], p = 0.005). Conclusions: LVI in gastric cancer is an independent prognostic factor, and its effect tends to be particularly strong in advanced cancer with lymph node metastasis. These patients may therefore require more effective adjuvant therapy.