We investigated the associations of perceived risk and cancer worry with colorectal cancer screening by the faecal occult blood test, colonoscopy or both. This study was based on the 2013 Korean National Cancer Screening Survey, including 2154 randomly selected, cancer-free and over 50-year-old adults. Individuals with higher cancer worry were 1.53 times more likely to undergo colorectal cancer screening, influenced by emotional reaction; individuals with greater perceived risk were 1.61 times more, affected by subjective awareness. However, cancer worry was only associated with the faecal occult blood test. Better understanding of cancer worry and perceived risk on screening behaviours may help to increase colorectal cancer screening rates.