Pharmacy services have traditionally consisted of dispensing, provision of drug information and inventory management practices. Pharmacist's impact on the implementation of medication safety standards, drug therapy optimization, and other clinical interventions has been adequately reviewed in settings of general wards and considered as standard practice; however, these activities in the operating room have not become the standard practice. In this article, we reviewed the clinical interventions by pharmacists working in the operating room. The five main duties or obligations required of the pharmacists are appropriate drug management, achieving medical economic benefits, mixing injectable drugs, risk management, and provision of drug information. The major information provided to physicians and nurses is on usage, dosage, stability, incompatibility, pharmacological effects and adverse effects. Physicians and nurses require the drug information provided by the pharmacist in the operating room. Furthermore, their requirement for the stationing of pharmacist is extremely high. It is suggested that these services might be quite important in optimizing drug therapy and preventing adverse effects. Additionally, pharmacist can contribute on rational use of drug, safety management, reduction of works of other medical staff, and also the medical economics through pharmaceutical care in operating room as well as in general wards. It is suggested that stationing pharmacists in the operating room might be indispensable for hospital administration in view of the medication safety and cost reduction.