Cancer is a leading cause of death, and the dietary pattern in Korea is changing rapidly from a traditional Korean diet to a Westernised diet. In the present study, we investigated the effects of dietary factors on cancer risk with a prospective cohort study. Among 26,815 individuals who participated in cancer screening examinations from September 2004 to December 2008, 8024 subjects who completed a self-administered questionnaire concerning demographic and lifestyle factors, and a 3 d food record were selected. As of September 2013, 387 cancer cases were identified from the National Cancer Registry System, and the remaining individuals were included in the control group. The hazard ratio (HR) of cancer for the subjects older than or equal to 50 years of age was higher (HR 1.80, 95% CI 1.41, 2.31; P< 0.0001) than that for the other subjects. Red meat consumption, Na intake and obesity (BMI ≥ 25 kg/m²) were positively associated with overall cancer incidence in men (HR 1.41, 95% CI 1.02, 1.94; P= 0.0382), gastric cancer (HR 2.34, 95% CI 1.06, 5.19; P= 0.0365) and thyroid cancer (HR 1.56, 95% CI 1.05, 2.31; P= 0.0270), respectively. Participants who had at least three dietary risk factors among the high intakes of red meat and Na, low intakes of vegetables and fruits, and obesity suggested by the World Cancer Research Fund/American Institute for Cancer Research at baseline tended to have a higher risk of cancer than the others (HR 1.26, 95% CI 0.99, 1.60; P= 0.0653). In summary, high intakes of red meat and Na were significant risk factors of cancer among Koreans.