This is a report on the Consensus Development Conference on adjuvant therapy for patients with colorectal carcinoma, which was held at the National Cancer Institute of the National Institutes of Health (NIH) in Bethesda, Maryland between April 16th and 18th 1990. Based on statistically significant results of a clinical trial adjuvant therapy with 5-fluorouracil (5-FU) and levamisole was recommended outside controlled clinical studies for patients with Dukes C colon carcinoma, but because no optimal form of adjuvant therapy yet exists there is still the need for further trials. No recommendations were given for patients with Dukes B colon carcinoma. For patients with Dukes B + C rectal cancer combined radiation therapy and 5-FU-based chemotherapy was considered "standard therapy" according to the consensus panel, but this recommendation seems to be still worth discussing. Since there is need of further evaluation of newly-recognized prognostic factors and also to optimize adjuvant strategies the panel stated that further prospective randomized studies are warranted. Hence, the establishment of a multicentre study group also in Austria appears to be an essential application of such trials in order to contribute towards ameliorating the prognosis of patients with colorectal carcinoma.