Abstract: Appropriate prophylactic administration of antibiotics for thoracic and cardiovascular surgical procedure can reduce postoperative morbidity and decrease the overall cost due to infections. Prophylactic antibiotics should be given within 30 minutes preceding incision intravascularly. Serum levels of free drug above the minimal inhibitory concentration (MIC) for common contaminating bacteria should be maintained for the entire surgical period. Prophylactic antibiotics after operation are useless for patients without risk factors predisposing to postoperative infection. Heart and(or) lung transplant patients should be given antiviral and antifungal prophylaxis. Selection of antibiotics must be based on the pharmacokinetic, pharcodynamic and pharmacoeconomic properties of antibiotics and features of surgery. The policy of antibiotic prophylaxis must be modified in response to alterations in antibiotic resistance pattern which is constantly changing in hospital.