Fears regarding prostate cancer and the associated screening are widespread. However, the relations between anxiety, cancer worry, and screening fear and screening behavior are complex, because anxieties stemming from different sources have different effects on behavior. In differentiating among anxieties from different sources (trait anxiety, cancer worry, and screening fear), we expected that cancer worry would be associated with more frequent screening, whereas fear of screening would be associated with less frequent screening. Hypotheses were tested in a sample of 533 men (ages 45-70 years) recruited using a stratified cluster-sampling plan. Men provided information on demographic and structural variables (age, education, income, marital status, physician discussion of risk and screening, access, and insurance) and completed a set of anxiety measures (trait anxiety, cancer worry, and screening fear). As expected, two-step multiple regressions controlling for demographics, health insurance status, physician discussion, and health-care system barriers showed that prostate-specific antigen and digital rectal examination frequencies had unique associations with cancer worry and screening fear. Specifically, whereas cancer worry was associated with more frequent screening, fear of screening was associated with less frequent screening at least for digital rectal examination; trait anxiety was inconsistently related to screening. Data are discussed in terms of their implications for male screening and the understanding of how anxiety motivates health behaviors. It is suggested that understanding the source of anxiety and the manner in which health behaviors such as cancer screenings may enhance or reduce felt anxiety is a likely key to understanding the associations between anxiety and behavioral outcomes. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1631 -9)