During the last two decades, many higher education systems in the world have attempted to evaluate and improve the quality of education, research and services at the university and higher education level. Countries which have been successful in these attempts have initiated continuous evaluation and applied internal evaluation as a basis for promoting quality culture. Quality assurance as a comprehensive term encompasses all policies, processes and actions maintaining and developing higher education quality. Quality assurance emphasizes on external goals of evaluation, one of which is to assure learners, public and government that each unit, department, program or institution manages its quality. Thus quality assurance focuses on accountability. In Iran, also, implementation of continuous evaluation projects started in 1996. Since then attempts were made to institutionalize departmental internal evaluation at the university level. The main purpose of this research was to conduct an "internal evaluation" of PhD program in Department of Persian Language and Literature of Tehran University This article describes importance of quality assurance and internal evaluation and the necessity to conduct it. (Contains 1 table and 1 figure.)