This study was conducted to identify adults' knowledge, attitude, dietary behavior, and lifestyle for cancer prevention, and to examine the relation between these variables. The participants were 414 adults in the Jeonbuk area. The data were analyzed using Pearson correlation coefficients, ANOVA and Duncan test with SPSS v. 12.0. The score for participants' knowledge about cancer was 23.98 points of a possible 30, the score for attitude towards cancer was 44.46 points of a possible 55, the score for preventive dietary behavior for cancer was 36.79 points of a possible 55, and their score for preventive lifestyle for cancer was 29.76 points of a possible 40. The knowledge, attitude towards cancer, dietary behavior, and lifestyle for cancer prevention showed significant differences according to the general characteristics (e.g., age, religion, monthly income, educational level, job, health condition, and interests). There was a significant positive correlation between knowledge about cancer, attitude towards cancer, dietary behavior, and lifestyle for cancer prevention. Dietary behavior for cancer prevention showed a positive correlation with lifestyle for cancer prevention. In conclusion, it is necessary to consider the related factors for the development and implementation of systematic education programs that can encourage and promote preventive health behavior for cancer among adults.