Objective: To investigate the expression of the inhibitor of differentiation/DNA binding-1 (ID-1) and its relations with Ki-67 and vascular endothelial growth factor (VEGF) in rectal cancer tissues as well as their clinical significance. Methods: The expressions of ID-1, Ki-67 and VEGF in rectal cancer tissues from 62 patients were detected by immunohistochemical staining and the relations among them were analyzed. Results: There were positive correlations between the expressions of ID-1 and Ki-67, ID-1 and VEGF, and Ki-67 and VEGF (r=0.89, 0.78, 0.92, all P<0.05), and the high expressions of these three proteins were associated with the degree of infiltration of the rectal cancer cells. Conclusion: The high expressions of ID-1, Ki67 and VEGF in rectal cancer tissues are possibly related to the invasion and metastasis of rectal cancer, and the detection of them may have certain significance in treatment and estimation of prognosis of rectal cancer.