Introduction: Effectiveness of COVID-19 vaccine in preventing COVID-19 and related mortality is to be studied in depth especially now since we are on the verge of 4th wave of pandemic. The present study aims to evaluate the effectiveness of vaccines in preventing case fatality in hospitalized COVID-19 patients in a tertiary care centre. Methods: A hospital based cross-sectional study was done in all COVID-19 patients admitted in a tertiary care centre in Aurangabad from February 2021 to May 2022. 1275 patients vaccination status was known and outcome of these patients were studied. Unadjusted Odds ratios for each variable were estimated and logistic regression was used for multivariate analysis. Results: 360 study participants (28.24%) had taken at least 1 dose of vaccine, while 915 (71.76%) were not vaccinated. 441 (34.59%) participants had unfavourable outcome (death). The mortality in vaccinated was 24.17% (87/360) while it was 38.69% (354/915) in unvaccinated. In logistic regression model, partial as well as complete vaccination, age<65, female sex, not having a comorbidity were associated with favourable outcome. Vaccine effectiveness for single dose and double dose was 37% and 66% respectively. Conclusions: It is observed that getting partially as well completely vaccinated was a protective factor for good recovery in COVID 19. Vaccine is found to be effective in preventing mortality in COVID patients.