Anal and transanal tumor operations are safe and are associated with a very low morbidity. Perianal and anal lesions as well as low rectal tumors can be excised by direct exposure using an anal retractor. For lesions situated in the middle or upper third of the rectum, special instrumentation, such as transanal endoscopic microsurgery (TEM) and transanal endoscopic operation (TEO) should be used to avoid unnecessary R1 resections. Fatal complications are extremely rare and most complications, such as urinary retention or temporary subfebrile temperatures, are minor. Suture line dehiscences are usually clinically unremarkable. Major complications comprise significant hemorrhage and opening of the peritoneal cavity. The latter must be recognized intraoperatively and can usually be managed by primary suturing. Infections, abscess formation, rectovaginal fistula, injury of the prostate or even urethra are extremely rare complications.