Background and Objective: Service satisfaction has been an index for indicating standard of patients care provision and had been used for evaluating the performance of the Department of Pharmacy of all hospital including Srinagarind Hospital which dispensed medications patients with Civil Servant Medical Benefit Scheme over 100,000 orders per year.Methodology: This study was a prospective descriptive study performed in patients with Civil Servant Medical Benefit Scheme who underwent outpatient pharmacy service at Srinagarind Hospital during 15 August to 15 September 2013. Structural questionnaires were used to survey the knowledge about privilege of medical benefit and the satisfaction to pharmacy service. Data were analyzed using descriptive statistics and presented in terms of mean/standard deviation and frequency/percentage.Result: There were 400 patients recruited into the present study. The respondents were 42.8% males and  57.2% females. Most of patients satisfied with the service in term of service provision behavior, service location, service speed and overall satisfaction with average score of 4.0, 4.0, 3.7 and 4.0, respectively (total score 5). Knowledge about the privilege of medical benefit showed average score of 3.7 (total score 7) and most of patients (43.2%) were classified as moderate level. In addition, knowledge about medication and service of medical benefit assessed showed average score of 4.58 (total score 13) and most of patients (51.8%) were classified as low level.Conclusion: Most of patients satisfied with the service of the Department of Pharmacy, Srinagarind Hospital meanwhile they lacked of knowledge about the privilege, medication and services under their medical benefit. 