We evaluated retrospectively the accuracy of endoscopic ultrasonography (EUS) in the preoperative staging of 63 patients with rectal cancer who were hospitalized and underwent surgery at our institution from January 1994 to December 1997. These patients, 39 men and 24 women with a mean age of 60 years, underwent preoperative EUS, which was performed in all cases using an echo-colonoscope Olympus CF UM 20, with a 7.5 MHz radial scanner. Ten patients did not undergo surgery and, therefore, were excluded from the analysis. EUS showed an overall accuracy of 81% for the T stage (including nontraversable stenotic tumors) and of 70% for the N stage. The accuracy of EUS for the T stage increased from 81 to 90% when we excluded those cases with nontraversable stenotic cancers from the analysis. Five tumors (9.4%) were understaged. while another five cases (9.4%) were overstaged. Finally, EUS was highly accurate (81%) in differentiating T1 from T24 tumors. In conclusion, our data shows that EUS is very accurate in the locoregional staging of rectal cancer and confirms the role of this imaging technique in the preoperative staging of patients with rectal cancer.