Abstract Background Colorectal cancer is the second most prevalent cause of death from malignancies globally. The present study was conducted targeting the influence of an educational intervention based on the health belief model (HBM) on colorectal cancer screening behaviors in people 50 years old and older. Methods All 134 samples were included in this quasi-experimental study from Fasa City Health Service Center, equal halves were random into experimental group and control group. The data collection tool was a questionnaire that contained questions on demographic variables, knowledge, and HBM constructs (perceived sensitivity, perceived intensity, perceived benefits, perceived barriers, self-efficacy, and screening behaviors). Both groups answered the questionnaire before and two months following the intervention. There were six 90-minute instruction sessions for the intervention group. SPSS 22 and descriptive and analytical tests (independent t-test, paired t-test, and Chi-square test) were used for data analysis ( P < 0.05). Results 59 women and 75 men took part in this study. A majority of participants were married and had at least high school diploma. The findings indicated that the mean scores for knowledge, each of the HBM’s constructs, and cancer screening behaviors did not differ significantly from one another before the intervention between the test group and the control group. However, post the intervention, the intervention group exhibited a significant rise in all mentioned dimensions. Conclusion In light of the outcomes, the application of the HBM on colorectal cancer screening behaviors in people 50 years and older was successful. This approach might serve as a helpful foundation for planning, carrying out, and overseeing colorectal cancer screening programs.