Diagnostic and treatment of rectal cancer need a continuous quality assessment. Indicators of quality were compiled as indicator profile for a summarizing evaluation. The indicators selected should potentially show an appreciable variation of the quality target and in addition should be decisive for the outcome. For the evaluation of the clinical diagnostic the frequency of the determination of the pretherapeutic T, N and M categories and the proportion of pT 1-tumors were chosen, for the pathological diagnostic the number of histologically examined lymph nodes and the proportion of lymphnode positive patients. Process quality of treatment was defined by the following indicators: proportion of tumor excision, of definite therapy by local tumor removal, of neo-adjuvant long-term radiochemotherapy, of adjuvant treatment in patients not selected for neoadjuvant therapy, of total / partial mesorectal excision, of abdomino-perineal resection, postoperative mortality, frequency of clinically apparent anastomotic leakage, and of neurogenic bladder dysfunction at hospital discharge. The indicators for the quality of the performance of treatment were differentiated between surrogate indicators that can be determined immediately after accomplishment of primary surgical therapy giving strong clues for the further course of disease at an early date, and definite indicators. Important surrogate indicators comprise the occurrence of intraoperative local tumor cell dissemination, R 1 / 2-resection, pathohistologically CRM-positive tumor resection, and the quality of mesorectal excision (proportion of incomplete mesorectal excision). The definite indicators include the 5-year local recurrence rate and the 5-year overall survival rate. The corresponding quantifying parameters for the individual indicators are specified in this paper with precise figures.