The aim of the Stockholm Colorectal Cancer Study Group is to improve treatment results in colorectal cancer. Between 1980 and 1993 the group conducted two randomised trials on preoperative radiotherapy in rectal cancer including 1406 patients. In both trials radiotherapy significantly reduced local recurrence and improved cancer specific survival. To further improve treatment results, four workshops have been held to introduce the "TME concept" to surgeons in Stockholm. The workshops included live surgical demonstrations and histopathology sessions. When patients included in the Stockholm trials (1980-1993) were compared to patients included in the "TME project" (1995-1996) the rate of abdominoperineal procedures was reduced from 60 to 27 per cent. Within two years of follow up the local recurrence rate was reduced from 15 to 6 per cent and cancer related deaths from 16 to 9 per cent. It is concluded that surgical teaching initiatives may have a significant impact on cancer outcomes.