Background & Objective: Evaluation is an essential process for educational institutions and one of the most common methods of evaluation of teachers is evaluation by students Students are the real customers in the educational process therefore their judgments should be important variables in determining teaching status of teachers According to customercentric principles the consumers satisfaction must be met This study assessed the validation of the current teacher evaluation form in theoretical courses Methods: This was a crosssectional study investigating the validity and reliability of the teacher evaluation form that is completed by students and identifying some factors affecting student evaluations To determine content validity of the teacher evaluation form 20 expert teachers were selected proportional to the number of teachers of each school of the Hamadan University of Medical Sciences To assess the reliability coefficient of the form 189 students were selected from different schools by proportional random sampling Results : According to the results questions such as rate of adherence to the determined topics providing practical application of teaching materials and the efficacy of determined assignments did not have the necessary validity score However the results indicated that validity of the questionnaire was acceptable In the present study the SpearmenBrown correlation coefficient indicated that the teacher evaluation form did not have an acceptable reliability (r = 0456 P < 0001) Conclusion: The current teacher evaluation form has an acceptable content validity but it does not seem reliable