Gender-specific differences in the risk of cancer for colorectal carcinoma result from the observation that males and females exhibit different responses to certain substances, whereby observations to date point to the influence of oestrogen. Cellbiological mechanisms causing this phenomenon are not as yet well understood. Additionally, there also exist gender-specific behavioural patterns, which influence the risk of cancer as well as the acceptance of certain arrangements for prevention, screening, therapy and follow-up of colorectal cancer. Until now, these differences have not attracted interest. There seems to be urgent need to integrate these observations into counselling and clinical care, as well as make them known to the general public.