Screening may be effective for reducing deaths due to prostate cancer. The aim of this study was determine the prevalence and determinants influencing prostate cancer early detection behaviors based on the theory planned behavior (TPB). In this cross-sectional study, conducted in the west of Iran, a total of 250 men aged 50 to 70 years old were randomly selected to participate. Of these, 200 (80%) signed the consent form and voluntarily agreed to take part. A structured questionnaire based on TPB constructs was applied for collecting data by interview. Analyses were conducted with SPSS version 16 using bivariate correlations, and logistic and linear regression. Some 26.5% of the participants demonstrated prostate cancer early detection behavior. Age higher than 60 (OR: 5.969), academic education (OR: 2.904), number of family members more than four (OR: 3.144), and knowledge about prostate cancer (OR: 3.693) were the most influential predictive factors for early detection behavior. Furthermore, among the TPB constructs, attitude (OR=1.090) and subjective norms (OR=1.280) were the most influential predictors. Attitude, subjective norms, and perceived behavioral control accounted for 43% of the variation in the outcome measure of the intention to screen for prostate cancer (adjusted R squared= 0.43, F= 49.270 and P < 0.001). Designing and implementation programs to increase positive attitudes and encourage subjective norms towards prostate cancer screening behavior may be useful for promotion of early detection.