Endorectal ultrasonography is a technique that visualize the rectal wall and perirectal tissues with a high degree of clarity. It is used for evaluation of rectal and perirectal diseases. It is a safe and accurate method for staging tumour invasion in patients affected by rectal cancer. It surpasses the accuracy of CT and MRI in preoperative staging of rectal carcinoma. It is also used as a part of the follow up procedure after colorectal surgery to detect local recurrence.