Transanal endoscopic microsurgery (TEMS) will play an even greater role in the treatment of rectal cancer as the UK national colorectal cancer screening program becomes national. With more rectal tumors being uncovered at earlier stages, a greater emphasis will be placed on treatment options that do not involve radical surgery and the possibility of a stoma. This article reviews the data surrounding TEMS, focusing on its current role in the treatment of early rectal cancer but with a view on how this option may develop in the future, particularly with regards to the more advanced rectal cancers and in view of the improved chemoradiotherapy regimens available. The data is reviewed and some of the more controversial issues discussed.