Objectives The present study aimed to examine whether demographic as well as psychosocial variables related to the five stages of change of the Transtheoretical Model can predict non‐clinical adults' cancer preventive and health‐promoting behaviors. This study specifically focused on cancer, one of the major chronic diseases, which is a serious threat of national health. Methods A total of 1530 adults participated in the study and completed questionnaires. Collected data were analyzed by using multinominal logistic regression. Results The significant predictors of later stages varied among the types of health‐promoting behaviors. Certain cancer preventive health‐promoting behaviors such as well‐balanced diet and exercise were significantly associated with psychosocial variables including cancer prevention‐related self‐efficacy, personality traits, psychosocial stress, and social support. On the other hand, smoking cessation and moderate or abstinence from drinking were more likely to be predicted by demographic variables including sex and age. Conclusions The present study found that in addition to self‐efficacy—a relatively well‐studied psychological variable—other personality traits and psychological factors including introversion, neuroticism, psychosocial stress, and social support also significantly predicted later stages of change with respect to cancer preventive health‐promoting behaviors. The implications of this study are also discussed. Copyright © 2013 John Wiley & Sons, Ltd.