Background: The novel coronavirus outbreak, caused by SARS-CoV-2, has proven to be an attack on the global healthcare system, demanding utmost attention from both the healthcare and government officials around the world. The use of face masks is so pivotal in lowering the risk of contracting respiratory viruses, it is crucial to know how many people are actually complying with this protective healthcare policy and what socio-demographic factors (if any) are influencing it. So, the aim was to investigate the adherence rate of face masks among the people of South Asian countries namely Pakistan, Bangladesh, and India, and also to examine correlations between face mask adherence and socio-demographic factors.Methodology: This was an observational study conducted from 15 July 2020 to 15 September 2020. Individuals of age more than 14 years of either gender, who had accessibility to the internet and understood English participated in the study. The three South-Asian countries such as Pakistan, India, and Bangladesh were targeted. The online survey form included questions regarding socio-demographics and the type of face mask they wore. Face mask adherence was classified as “yes” when any type of face mask was worn and “no” when no face mask was used. Statistical software SPSS version 25 was used to analyze data.Results: The mean age of the participants was 31.32±9.83 years. Out of all these participants, there were 826 (46.3%) males and 959 (53.7%) were females. Univariate analysis showed that females, Muslims, education level till graduate, employed, monthly income and Bangladeshi participants had higher odds of face mask adherence (p<0.05). The multivariate analysis showed that females, Muslims, urban residents, secondary level education, employed, monthly income $100 - $300, and Bangladeshi were strongly associated with face mask adherence (p<0.05).Conclusion: Among all three countries, Bangladeshi had high face mask adherence than Pakistan and India. The socio-demographic factors associated with facemask usage were gender, religion, locality, education, employment status, monthly income, and nationality.