Lynch syndrome (LS) is an autosomal dominant disorder caused by a mutation in one of the mismatch repair genes. Mutation carriers have a life-time risk of developing colorectal cancer (CRC) of between 25 and 75 %. Since the importance of a centralized organization of surveillance was emphasized in the late 1980s, the number of registered LS families with a known mutation has increased enormously worldwide. Large-scale surveillance programs of these families have achieved a 62 % reduction in incidence of CRC and a 65-70 % decrease in mortality. Nevertheless, the risk of CRC is still substantial even when included in a program and the most optimal surveillance interval for gene carriers remains unknown. Hopefully, improvements in high quality colonoscopy and new endoscopic visualization techniques will further reduce CRC risk in those included in a surveillance program.