Objective In 1995, an analysis showed an inferior prognosis after rectal cancer in Denmark compared with the other Scandinavian countries. The Danish Colorectal Cancer Group (DCCG) was established with the aim of improving the prognosis, and in this study we present a survival analysis of patients treated from 1994 to 2006. Method The study was based on the National Rectal Cancer Registry and the National Colorectal Cancer Database, supplemented with data from the Central Population Registry. The analysis included actuarial overall and relative survival. Results A total of 10 632 patients were operated on. The overall 5-year survival increased from 0.37 in 1994 to 0.51% in 2006; the improvement was greater in men (20% points) than in women (10% points), and greatest in stage III (20% points). The relative 5-year survival increased from 0.46 to 0.62, including an improvement of 23% points in men and 9% points in women and the greatest in stage III (22% points). Conclusions The prognosis has improved substantially, probably mainly because of initiatives taken by the DCCG, among which implementation of total mesorectal excision, improved staging and centralized treatment are considered most important.