Background: Sexual health is a necessary part of any society because it significantly influences the quality of life. Women's knowledge regarding STIs and safe sex practices in Saudi Arabia has not been thoroughly investigated; therefore, this study aims to investigate and measure the knowledge and the determinants of sexual health and STIs among women in Saudi Arabia.

Methods: This study is a nationwide cross-sectional survey conducted through phone interviews in Saudi Arabia in 2021. This study included 1334 female participants aged 18 years or older.

Results: The study's results collectively show that women in Saudi Arabia have limited knowledge of sexual health and STIs. The primary causes are the lack of knowledge of different STIs-communicability, symptoms, and an overall lack of technical proficiency in the subject. The study analyzed factors associated with participants' knowledge of sexual health and sexually transmitted infections. Significant associations were found between knowledge and age, region, educational level, and family income. In the multivariable analysis, participants aged 20-29 had higher knowledge compared to those aged >60. Participants in the Eastern region had higher knowledge than those in the Southern region. Participants with less than a bachelor's degree had lower knowledge than those with a bachelor's degree or higher. Participants earning an average of 16,000 SAR to 19,999 SAR had higher knowledge than those with unstable monthly income.

Conclusion: The study found that women's understanding of sexual health and STIs in Saudi Arabia is low due to a lack of knowledge and awareness. Knowledge levels were correlated with educational levels; therefore, targeted health promotion initiatives are needed to increase understanding, particularly regarding condom use for HIV and STI prevention.