ABSTRACT
Theses are considered as one of the main sources of information. The aim of this study was to evaluate the characteristics and structures of students' theses as well as their research methodology. In this descriptive study, all dentistry students' theses from the year 1998 till the year 2004 [176 theses], were investigated based on the aspects of thesis' structure, research methodology, and the results. Thirty seven point five percent of theses were descriptive, 17.6% were experimental, 16.5% were descriptive-inferential, 6.8% were inferential, and 8% were clinical trials studies. Ten point two percent of the theses gained excellent quality score, 64.8 percent gained good quality score, 24.2 percent gained moderate quality score, and 0.6 percent gained poor quality score in writing and research methodology. More supervision should be placed on theses quality by supervisors. It is also suggested to encourage students towards inferential and experimental studies. Moreover, the need to train students in regard to research methodology and statistics is emphasized and it is recommended to develop a comprehensive guideline for writing theses