Background: The severe acute respiratory syndrome corona virus-2 (SARS CoV-2) disease pandemic has been a threat to public health and health care system world-wide including routine immunization which has been greatly disrupted putting children at risk for vaccine-preventable diseases (VPDs). A study with an aim to analyse the impact of COVID-19 pandemic on routine immunization coverage post lockdown at a tertiary care centre of western UP.Methods: A retrospective analytical study was conducted at LLRM Medical College, Meerut comparing 3 periods of year 2020, each of 4 weeks viz: 1-28th of February, 1-28 of August and 1-28 of December.Results: Total number of vaccine beneficiaries decreased significantly post lockdown from 646 in February to 275 and 419 in August and December respectively. The percent reduction was maximally seen in booster vaccines while birth dose group was least affected. There was 76.2% and 39.3% reduction in number of children receiving primary doses of combination vaccines in August and December period respectively as compared to February 2020. We found 68.42% and 54.39 % reduction in MR-1 beneficiaries in August and December respectively as compared to February 2020.Conclusions: Significant reduction is found in total number of children receiving immunization during un-lockdown period, compared to pre-COVID level. This difference was more significant in booster doses compared to birth doses. We did not find any significant catch up in vaccine beneficiaries by December 2020 despite 7 months of un-lockdown raising significant concern for public health.