Colorectal cancer is a second commonest tumor in Hong Kong and the second commonest cause of cancer related death. About 1 in 23 males will develop colorectal cancer in his life time. The disease tends to cluster in families. This may be a combination of factors including shared genes, shared environment or chance. Known familial syndromes occur in only about 5% of cases. The majority is not well understood and labelled sporadic colorectal cancer. The screening strategy in families of subjects with colorectal cancer has not been defined. Colonoscopy is among the most sensitive and specific screening tool for colorectal neoplasm. The current study determines the prevalence of adenomas among first degree relatives of patients diagnosed with colorectal cancer. To quantify risk in this cohort, a case control analysis is used. The prevalence of the cohort is compared to that of a control population. The control group consists of relatives of patients with normal colonoscopic findings during the same study period.