The spread of SARS-COVID 19 infection has resulted in accelerated efforts at development and dissemination of vaccines throughout the globe. These vaccines have different mechanisms of actions and their efficacy and side effects are being monitored. There have been rare reports in literature of thyroid dysfunction after COVID-19 vaccine administration. Sub-acute thyroiditis is one such complication which can arise as a rare side-effect of vaccination. This has also been reported as a symptom of COVID-19 infection. Clinical features include fever, neck pain, palpitations and weight loss. We report sub-acute thyroiditis in a 50-year-old male who presented with symptoms suggestive of thyroid abnormality one day after receiving the inactivated COVID-19 vaccine (CoronaVac Sinovac-Biotech Ltd).