Background: The occurrence of early childhood caries in children may be influenced by the oral health practices and awareness of mothers. It can be supportive and helpful to mothers to understand their knowledge and habits surrounding their children's dental issues so they can better care for their children.. Aim: To evaluate the effect of social-platform-based educational guidelines on first-time mothers' knowledge and practices regarding their children's oral health. Design: This study was conducted using a quasi-experimental research design. Setting: This study was implemented at Sohag City, Egypt. Sample: A purposive sample of 400 mothers was used to gather data, on their children in the first year of life during December 2023 from 10 and 30 by using an online questionnaire via Google Form. Tools: Three tools were utilized: Tool I: First-time mothers' knowledge questionnaire which included two parts; part one: mothers' demographic data and part two: mothers' knowledge regarding oral health, Tool II: First-time mothers' practice regarding oral health, Tool III, Mothers' satisfaction with social-platform based educational guidelines interventions. Results: The results of the study showed that first-time mothers were mainly aged 21 < 26 (73.0%), 49% of them had a secondary education, unemployed (58.0%), and 89% were from urban. a higher score of knowledge and practice was found among first-time mothers post-social-platform-based educational guidelines compared to pre-social-platform-based educational guidelines regarding oral health. A positive correlation was detected between First-time mothers' total knowledge and reported practice scores at <0.001 regarding oral health post-social-platform-based educational guidelines. Conclusion: The study concluded that social-platform-based educational guidelines have a positive effect on improving first-time mothers' knowledge and practice regarding their children's oral health. Recommendations: Providing first-time mothers with a well-planned health education program to improve their knowledge and reported practice regarding their children's oral health and reinforce possible educational actions, especially in early motherhood, are important to achieve this improvement and to decrease early childhood caries rates.