Background: COVID-19 has disrupted immunization activities across the world. There is lack of data from India about the impact of COVID-19 on vaccination ,particularly at the ground level.Hence we aimed to study the impact of COVID-19 on immunization at a public tertiary care teaching hospital. Methods: This is a pre and post lockdown data analysis study. The data analyzed included period before lockdown from 1st January 2020 to 24th March 2020 (“Period 1”) and during lockdown from 25th March 2020 to13th May 2020(“Period 2”) from the immunization OPD of a public tertiary care teaching hospital from Western India. Cumulative doses of vaccines given at weekly intervals during two periods (period 1 and period 2) were tallied. The reduction in number of vaccines given during the two time periods in three vaccine groups viz. vaccines given at birth,vaccines given in infancy and under five children( except MR) and MR vaccine. Results: Our study shows that there was some decline in the number of vaccines given to newborns in hospital, however, this was not statistically significant (p>0.05). Compared to this, there was a major impact on number of vaccines given in infancy and under five children (p <0.005). We specifically studied impact on the MR vaccine and found there was statistically significant decline in number of children immunized (p <0.007). Conclusions: There was a major impact of COVID-19 lockdown on vaccines given to infants and children.