The severe acute respiratory syndrome coronavirus 2 pandemic started in December 2019, spread like wildfire and took an immense toll on human life. ChAdOx1 nCoV-19 vaccine was used worldwide for the prevention of Covid-19. Covid-19 has been implicated in the causation of severe haemophagocytic lymphohistiocytosis (HLH) syndrome. However, the same has not been reported with ChAdOx1 nCoV-19 vaccine in the literature. We report a young man who developed secondary HLH post-ChAdOx1 nCoV-19 vaccination.