Correct staging of adenocarcinoma of the rectum is mandatory before any therapeutic choice is made. Important features are infiltration of the perirectal fatty tissue (T3 and T4) and the presence of locoregional lymphatic spread. Computed tomography with rectal air insufflation (CT) was compared with transrectal ultrasonography (TRUS) in 212 patients. Results of the preoperative examinations were compared with histological findings. The CT examination in evaluation of perirectal spread had an accuracy rate of 76%, sensitivity of 86% and specificity of 62%, the corresponding figures for TRUS were 83%, 91% and 66%. The accuracy, sensitivity and specificity of CT for nodal involvement were 51%, 57% and 50% and of TRUS 60%, 68% and 59%. These findings confirm that TRUS is more accurate than CT in local tumour staging (T) and in detecting nodal spread (A).