['To compare digital examination, endoluminal ultrasound (ELU), and plain magnetic resonance imaging (MRI), with histopathological findings in the preoperative staging of rectal cancer.', 'A prospective comparative study.', 'University hospital, Sweden.', '35 patients with rectal cancer who presented during the period February 1987 to February 1991.', 'The digital examination of 19 patients could be assessed and was correct in 13 (68%). ELU was done in 34 patients; the accuracy was 88%. Extension of tumour was overestimated in two and underestimated in two. MRI was done for 35 patients with an accuracy of 66%; in 12 patients extension was underestimated. The diagnostic accuracy of the assessment of lymph node involvement was 71% with ELU, and 72% with MRI.'] Are endoluminal ultrasound and low-field magnetic resonance imaging superior to clinical examination in the preoperative staging of rectal cancer?