Background. Little data exist about the prognostic role of a lymphatic vessel invasion (LVI) in patients with esophageal carcinoma. The objective of this study was to clarify the presence and prognostic impact of LVI in a large group of patients resected for esophageal squamous cell carcinoma (SCC) at one surgical center. Methods. Three hundred sixty-six patients, who had a primary resection for SCC, were analyzed by univariate and multivariate analysis. Follow-up was complete for 93.7% patients with a median follow-up of 8.3 years. Results. The total rate of LVI was 39.1% (n=143). Univariate analysis revealed a significant relation between LVI and different T classifications (P=0.001), N classifications (P<0.0001), M classifications (P<0.0001), International Union Against Cancer (UICC) stages (P<0.0001), and residual tumor (P<0.0001). Multivariate analysis of the patients with RO-resected tumors proved LVI as an independent prognostic factor. The 2-, 5- and 10-year survival rates in patients with LVI were 28.5%, 11.1%, and 9.2% compared with 63.4%, 46.6%, and 27%, respectively, without LVI (P<0.0001). Patients with LVI had a median survival time of 11.4 months compared with 28.6 months without LVI (P<0.0001). Patients with R0-resected tumors without LVI had a median survival time of 54.1 months compared with 12.1 months in patients with LVI (P<0.0001) and compared with 11.3 months in patients with R1-resected tumors P<0.0001). Conclusions. These data clearly show that LVI is an independent prognostic factor in patients with SCC and confirm the importance of a systematic pathohistologic workup. The prognosis of patients with R0-resected tumors with LVI is equal to patients with an incomplete tumor resection. This supports the inclusion of LVI in the UICC classification system for esophageal carcinoma. Cancer 2001;92: 2228-33. (C) 2001 American Cancer Society.