BackgroundMalaria disease is one of the most dangerous protozoan parasitic infections with a high mortality rate in developing countries. Malaria is a public health issue, especially in Hormozgan province, and is highly affected by foreign immigrants (Pakistani and Afghani); thus, the present study aimed to evaluate the effect of an intervention based on the health belief model (HBM) on the promotion of malaria prevention behaviors in Afghani immigrants over the age of 18. The participants resided in Persian city in Hormozgan province.MethodsThe present quasi-experimental study was conducted on 200 Afghans immigrants over 18 years of age who visited four comprehensive health service centers in Parsian city, south of Iran in June until December 2023. Sampling was by cluster method. In this way, the health centers were considered as clusters, and then 4 centers were randomly selected from among them (two centers of the control group and two centers of the intervention group) and participants were selected by a systematic random method by list of records in the National Integrated Health Record System (called SIB) (100participants control group, 100 participants intervention group). The data were collected using a researcher-made questionnaire based on the HBM before and after the educational intervention An educational program was designed and implemented to promote preventive behaviors against malaria in five sessions using different strategies and based on the HBM for the intervention group. The data were analyzed using independent-samples T-test, paired-samples T-test, Pearson’s correlation coefficient, analysis of covariance and linear regression. All statistical analyses and hypothesis testing were done in IBM SPSS version 25, at a significance level of 0.05.ResultsIn the intervention group, there was a significant difference in the mean scores of knowledge (6.48, 95% CI: 5.9,7.05), perceived susceptibility (10.57, 95% CI: 10.03, 11.1), perceived severity (16.61, 95% CI: 15.83, 16.83), perceived self-efficacy (18.26, 95% CI: 17.55, 18.96), perceived benefits (15.43, 95% CI: 14.68, 16.17), perceived barriers (-22.49, 95% CI: -23.63, -21.30), cues to action (15.06, 95% CI: 14.36, 15.75), and preventive behaviors (20.05, 95% CI: 19.44, 20.65), before and after the educational intervention. P-value < 0.001. The regression analysis showed that the constructs of perceived susceptibility (T = 4.72, P < 0.001), cues to action (T = 5.30, P < 0.001)and perceived self-efficacy (T = 4.93, P < 0.001) led to the greatest change in malaria prevention behaviors(R-Square = 0.549).ConclusionThe present findings showed that the HBM -based intervention was effective in preventive behaviors against malaria in Afghans. It is recommended to design suitable educational interventions in order to increase the perceived susceptibility, cues to action and self-efficacy in order to improve preventive behaviors against malaria in Afghans.