Radon, a naturally occurring radioactive gas, poses a significant public health risk. This study aimed to assess indoor radon exposure in Saudi Arabia using the health belief model (HBM) as a framework for understanding and influencing public behaviour regarding the prevention on indoor radon exposure.A cross-sectional analytical study was conducted involving 803 participants from diverse backgrounds recruited through convenience sampling. The online questionnaire assessed sociodemographics, risk factors, and HBM constructs (perceived susceptibility, barriers, benefits, seriousness, and self-efficacy). Statistical analysis was conducted using SPSS.Most participants showed neutral perceptions towards susceptibility, severity (82.7% each), benefits (85.2%), and barriers (59.7%) to preventive practices. Only 31.6% had high self-efficacy, with 16.4% practicing good prevention and 44.3% fair. Preventive practices correlated positively with perceived severity, benefits, and self-efficacy, but negatively with risk score and perceived barriers.The study highlights the need for improved radon prevention practices in Saudi Arabia, focusing on educational campaigns, self-efficacy enhancement, policy support for renters, and better risk communication. These measures are crucial for mitigating radon exposure risks across the population.