Some 50 total mesorectal excision specimens were examined following rectal excision for cancer. Circumferential margin involvement was rare, but mesorectal tumour deposits were present in 17 of 44 patients with pT3 tumours, and 23 of 44 had mesorectal nodal involvement. No patient with a pT2 tumour had mesorectal involvement. Failure to excise the mesorectum completely has the potential to leave gross or microscopic residual disease that may in theory predispose to local failure. Total mesorectal excision is necessary to avoid incomplete pathological evaluation of the mesorectum and understaging of rectal cancer.