Background: Prosthetic heart valve thrombosis (PHVT) is a very rare complication after the replacement of a damaged valve by a mechanical valve. It contributes significantly to the late morbidity and mortality after heart valve surgery. The incidence varies across the world depending on the type of mechanical heart valve and its position. A little study was done on the absolute eosinophil count in prosthetic heart valve thrombosis. So in the present study, we are evaluating the risk factors, clinical profile and levels of absolute eosinophil count in prosthetic heart valve thrombosis cases