Surgical site infection (SSI) previously termed post operative wound infection is defined as that infection presenting up to 30 days after a surgical procedure if no prosthetic is placed and up to 1 year if a Prosthetic is implanted in the patient. SSI results in patient discomfort, prolonged length of hospital stay and increased cost. In other reports SSI was found to be second only to urinary tract infection as the commonest hospital acquired infection and actually the most commonly encountered form of nosocomial infection in surgical patients. These include the degree of microbial contamination of the operation site indicated by wound class as clean, clean contaminated, contaminated and dirty, and also by patient age, sex and duration of surgery The aim of this study is to investigate the risk factors for SSI together with the identification of the etiological bacterial agents and their antimicrobial susceptibility in a major teaching hospital in Tertiary Care Hospital. To the best of our knowledge, local studies focusing on bacterial isolates incriminated in SSI and their antimicrobial susceptibility are scanty.