Background: A novel corona virus disease known as COVID-19 has been declared a pandemic and a global health emergency by the WHO. The COVID-19 vaccination was first administered in India on January 16, 2021. India's well-organized immunization program and high vaccination coverage are well-known internationally. Aim: To determine the level of knowledge with attitude regarding COVID-19 vaccination among adults in suburban areas of Mumbai Metropolitan Region. Methodology: This Non-experimental descriptive research design involved 359 adults using a self-structured questionnaire to assess knowledge and the standard VAX scale used to assess attitudes regarding COVID -19 vaccination. Results: A total of 359 adults participated in the study, out of the total participants 41% have average knowledge regarding COVID-19 vaccination (mean knowledge score= 14.39; SD=4.0), high knowledge scores associated with male gender, people who speak the local language and those who working as medical personnel at p-value <0.05 significance level. The study showed that 77.44% of participants have a positive attitude towards COVID-19 vaccination (mean attitude score=27.93; SD=5.67)and there is an association with demographical variables. Conclusion: The current study revealed that even though knowledge regarding COVID-19 vaccination is average, the majority of the participants have positive attitudes toward vaccination. This finding can help the Policymakers to make plans for the next initiatives to promote vaccination uptake that could eventually result in herd immunity against COVID-19 in the pandemic era.