Aim: Prevention-focused school dental health program (SDHP) is a cost-effective intervention that countries can use to lessen the problem of dental diseases by educating on oral health. The current study aims to assess the effectiveness of parental participation in an SDHP held at periodic intervals on the oral health status (OHS) of children aged 8–10 years attending a local school in Southern India. Materials and methods: The longitudinal study was scheduled between September 2018 and June 2019 (36 weeks) in 120 participants who were healthy school children aged 8–10 years at a private school in Kelambakkam. This 36-week duration study assessed the effectiveness of school dental health education program with and without parents at every 12 weeks interval. The OHS of subjects was assessed using the standard indices [i.e., Decayed, Missing and Filled permanent teeth (DMFT), decayed, extracted, and filled primary teeth (deft), and Simplified Oral Hygiene Index (OHI-S)]. Friedman's test and Mann–Whitney U test were used for analyzing the data as indicated. Results: In postintervention visits, children with parental participation had significantly lower caries increments than children without parental participation. While the oral hygiene index scores have improved significantly in both groups over time, the improvement in the parental participation group was greater. Conclusion: It can be concluded that the SDHP is an educational driver that showed a constructive impression on the oral health of children. The participation of the child's parents in SDHP has significantly improved the OHS of children.