BackgroundCervical cancer is one of the most common cancers in women worldwide and a cause of high mortality among people. Pap smear screening is an appropriate method to prevent cervical cancer and reduce its mortality.AimThis study aimed to determine the effect of web‐based education based on the Health Belief Model (HBM) on cervical cancer screening behavior in middle‐aged women.Methods and ResultsThis study is a quasi‐experimental interventional research that was conducted on 240 middle‐aged women aged 40–59 years in Isfahan, Iran, in 2022. An online educational intervention based on the constructs of the Health Belief Model was conducted for the intervention group using the Triple‐B platform. The information on the intervention and control groups was collected before, immediately after the intervention, and 2 months later using a valid questionnaire. The gathered Data was analyzed using ANOVA and LSD post‐hoc, independent samples t test, chi‐square, and MANCOVA statistical tests in SPSS 26 software. After the intervention, the mean scores of knowledge, perceived susceptibility, perceived severity, perceived benefits, self‐efficacy, and internal cues to action in the intervention group increased and the mean score of perceived barriers decreased (p < .001). The mean score of the external cues to action did not show a significant difference between the intervention and control groups before, immediately, and 2 months after the intervention. Two months after the intervention, 32 women (26.2%) in the intervention group and two women (1.7%) in the control group performed the Pap smear test.ConclusionWeb‐based educational intervention based on HBM using different strategies such as question and answer, presentation of infographics, lectures, brainstorming, showing videos and numerous educational images can be an effective way for increasing knowledge and cognitive variables of women and doing Pap smear test.