BACKGROUND: Antimicrobial prophylaxis in cardiac surgery has been demonstrated to lower the incidence of surgical site infection (SSI). Inappropriate antimicrobial prophylaxis, such as inappropriate selection of the antimicrobial agent or inappropriate dosing regimen, can increase the prevalence of antibiotic resistant strains, prolong hospital stay, cause adverse reactions, and negatively affect an institution's pharmacy budget for antibiotics. In developing countries such as Jordan, where the role of clinical pharmacists is still in its primary stages, the first step in establishing an organized clinical pharmacy service is the evaluation of current practice to determine the need for improvement.