OBJECTIVE: When selecting patients who are at high risk for lymph node metastasis, the detection of lymphatic vessel invasion (LVI) is important. We investigated LVI detected by D2-40 staining as a predictor of lymph node metastasis in T1 colorectal cancer. MATERIALS AND METHODS: Clinicopathological factors including LVI were investigated in 136 patients who underwent colectomy with lymph node dissection for T1 colorectal cancer. We used immunostaining with monoclonal antibody D2-40 to detect LVI. RESULTS: Lymph node metastases were found in 18 patients (13.2%), and LVI were detected in 45 (33%); lymph node metastasis was more frequently observed in LVI-positive groups (13/45 vs 5/91, p < 0.001). Both univariate and multivariate analyses revealed that LVI detected by D2-40 and a poorly differentiated histology at the invasion front were independent risk factors of lymph node metastasis. CONCLUSION: LVI detected by D2-40 is important for the prediction of lymph node metastasis.