Background and objective:
The increase in drugs numbers and their complexity and the potential of drugs interactions have increased the need for the introduction of a unique clinical pharmacy services. Having a clinical pharmacist in all health care settings in general and in hospitals in specific is important to promote the rational use of medicines and to increase the awareness about the potential harms of medicines. This study aimed to find out the acceptance rate of physicians to clinical pharmacy interventions and cost avoidance resulting from clinical pharmacy interventions.

Methods:
An interventional, follow up study was performed over a period of 6 months using well-constructed clinical pharmacy interventions note form in surgery department at An-Najah National University Teaching hospital in Palestine, the acceptance rate of clinical pharmacy interventions was calculated. the cost of each prescription was calculated before and after each intervention to find out the cost avoidance from every intervention and to calculate the cost avoidance from overall interventions.

Results:
313 interventions were done of the 1075 the admissions to the surgery department. The most prevalent interventions were changing the regimen as the clinical pharmacist saw that it was not appropriate, followed by the conversion of the dosage form for the patient from the Intravenous (I.V) route into the oral route. Physicians in the surgical department were seen highly cooperative and accepted by 97.70 %. The reduction in the average daily drug costs throughout the period of 6 months followed the application of clinical pharmacy interventions was clear. some interventions resulted in clear cost reductions; others had minor reductions.

Conclusion:
Clinical pharmacy practice has the potential to reduce costs and ensuring rational use of drugs.