Irrational antibiotic use in surgical prophylaxis is of global concern due to the emergence of bacterial resistance and high healthcare costs. This study was done to compare the use of surgical antibiotic prophylaxis in a tertiary hospital with two international guidelines, American Society of Health-System Pharmacists (ASHP) and the Society of Thoracic Surgeons (STS) and the hospital antibiotic policy. A sample of 41 surgical patients was studied. The criteria used for comparison are the timing of the first dose of antibiotic, the choice and dosage of antibiotic used, intra-operative re-dosing and the duration of prophylaxis. The timing of the first prophylactic dose in 87% of the cases was as per the guidelines and the hospital antibiotic policy. The choice of antibiotic was right in 85.37% and 100% cases according to the ASHP and the STS guidelines, respectively. Continuous audits, physician education, providing written protocols and other interventions can improve the rationality of use of surgical antibiotic prophylaxis and conformance to the AHSP and STS guidelines.