Advances in surgical technique and knowledge of tumor biology have led to an algorithm of surgical treatment of rectal cancer, which offers three options: transanal local excision, sphincter-saving procedures (low anterior resection and, recently, intersphincteric abdomino-peranal resection), and abdomino-perineal resection of the rectum. The choice of operative procedure aiming to fulfill both oncological and functional criteria is determined by the anatomic location of the tumor, the tumor differentiation, the depth of tumor invasion, and preoperative anal sphincter function. Following the algorithm of treatment, a clear decrease can be noted during recent years in the number of abdomino-perineal resections and a shift towards sphincter-sparing procedures, without jeopardizing long-term survival. Although anal sphincter morphology can usually be maintained, preserving the anal sphincter does not necessarily mean preserving the sphincter function. The functional outcome must be judged by objective, measurable parameters and by the impact of operative sequelae on quality of life and its acceptance by the patient. Future work must focus on further improving long-term survival and functional outcome. Technical advances (Goligher et al. 1979; Heald 1980) and an improved understanding of tumor biology, especially metastatic behavior, have resulted in varied strategies for the operative treatment of rectal cancer. The common aims of these techniques are local control, avoidance of local recurrence, and--while still satisfying oncologic requirements--preservation of the anal sphincter. Until the 1970s, abdominoperineal excision was the treatment of choice. Subsequently, a shift toward anterior and low anterior resection of the rectum took place. Initially these procedures were limited to the treatment of tumors in the upper and mid rectum (Table 1) (Gall and Hermanek 1992), but the indication for anterior resection was later extended to tumors of the lower rectum (Table 2) (Hohenberger and Hermanek 1992).