Objective: Social media usage is a global consumer phenomenon that has risen exponentially in the last few years. Published Indian studies on social media addiction are scarce and social media associated health issues are an emerging health problem in India. Objectives: To assess and compare social media addiction between private and public high-school students and to assess health problems related to social media usage across these groups. Methods: This crosssectional study was completed in 2016. It was conducted in five private and five public high schools across wards of Bengaluru city that were selected by simple random sampling. The subjects were students studying in grades 8, 9 and 10 (aged between 12 and 16 years). A total of 760 subjects were recruited, 380 from public and 380 from private high schools. They were administered a pretested, semi-structured, self-administrated questionnaire in either the local language or English. Univariate and multivariate logistic regression were employed to establish any associations between social media addiction and various other factors. Results: In our samples, 60.95% of social media users studied in private schools and 39.05% in public schools (z = 10.31, p<0.001). The most commonly used social media applications were, Internet gaming (69.23%) in Public schools and WhatsApp (61.15%) in Private schools. The overall prevalence of social media addiction was 19.96% among users with significantly higher rates of selfreported addiction in private schools (z = 3.47, p < 0.001). A total of 70.67% of the subjects had one or more physical symptoms, i.e. neck pain, tension, strain on eyes and fatigue of which 67.42% and 72.75% were from public and private schools, respectively. Psychological changes, i.e. anger, lonely and frustration; and behavioural changes, i.e. sleep disturbance and neglect personal hygiene were observed in 67.42% and 51.01% of public and private school pupils, (z = 3.85, p < 0.001), respectively. Conclusion: Private school students were more prone for social media addiction. Majority had mild addiction. Addiction was associated with behavioural changes. A multitude of physical, psychological and behavioural problems were observed among social media users.