Approximately one in three to four patients with a colorectal carcinoma has an increased risk of malnutrition. The two screening methods calculated a different prevalence (23 and 38 %). Any malnutrition that is present demonstrably has a significant impact both on the rate of complications and the length of stay and may therefore have a decisive influence on the costs. The results of this multicenter study underscore the need for systematic screening for malnutrition and at the same time should increase clinics awareness of the importance of establishing a nutrition management policy.