Background: Self-medication is defined by the World Health Organization (WHO) as using medications to treat self-diagnosed conditions or symptoms, as well as intermittently or continuously taking prescribed medicines for recurrent or chronic illnesses or symptoms after the recommended dosage has been completed. Purposes:  To assess mothers' knowledge and administration of Over-the-counter medications during pregnancy at Al-Baha region in Saudi Arabia. Design: A descriptive cross-sectional hospital-based study was utilized. Sampling: it included three hundred and ninety-eight postpartum mothers. Results: most (n=233) of the participants were aware and had good knowledge about the Over-the-counter medications, nearly half of the participants (n=167) used those medications even though they knew their side effects. Conclusion: This study concluded that most of the study group used over-the-counter medications despite of their harms and risks during pregnancy, even in the first trimester. Recommendations: Health education campaigns should be conducted at all levels of the community and in workplaces of women to raise their awareness of the harms and risks of using over-the-counter medications during pregnancy and Future studies with different designs should be conducted to search the awareness, attitude, perception, and practice of pregnant women about over-the-counter medications used during pregnancy are highly recommended.