Abstract: Objective : To assess the accuracy and limitations of endoluminal ultrasonography (ELUS) in preoperative staging of rectal cancer. Methods : ELUS was performed preoperatively in 58 patients with rectal carcinoma, in which no preoperative treatment was given. The results of ELUS correlated with operative and pathologic findings according to the TNM classification. Results : The overall accuracy of ELUS in T stage was 79.3%. The sensitivity of ELUS for T₁, T₂, T₃ and T₄ carcinoma was 100%, 58.8%, 87.5%, 83.3%, respectively. The sensitivity for T₂ carcinoma was the lowest, and overstaging as a T₃ carcinoma occurred in 6 of 7 patients being misdiagnosed, which were ulcerative adenocarcinoma. The sensitivity, specificity and accuracy of ELUS in lymph node metastasis were 76.9%, 75.0%, 75.9%, respectively. The diagnosis of ELUS in lymph nodes metastasis was false negative in 6 patients and was false positive in 7 patients. Conclusion : The ELUS should become an important imaging tool in the preoperative assessment of the depth of tumor invasion and lymph node metastasis of rectal carcinoma. The overstaging of T₂ carcinoma is an important unfavourable factor in assessing the invasion depth with ELUS, In addition, rectal stenosis caused by carcinoma and tumor locating in the superior segment of rectum also decrease the accuracy of ELUS.