Researches had shown that the use of antibiotic prophylaxis in cardiac surgery is very helpful against post-operative infections. The hospital in which this research has been conducted was using both “Vancomycin and Gracil” antibiotics per-post operatively. Some surgeons recommend 3 doses i.e. to continue the antibiotics for 24 hours (1 dose before operation, 2nd dose after operation, and 3rd dose if necessary). Some surgeons practice to continue them for 48 hours and some continue them even for 6 - 10 days post-operatively. 1 dose of antibiotic costs PKR 1000 R.S, it means that the patients who are receiving these antibiotics for 10 days, have to spend extra PKR 30,000 R.S. Whereas, the literature loudly supports that there is very less evidence to continue the antibiotic doses 48 hours after cardiac surgery. The research was designed to study, if continuing antibiotic prophylaxis for less than 48 hours is sufficient for patients undergoing cardiac surgery.