Background and objective: The most important goals of examinations are improvement of quality educational programs. The OSCE method is also an appropriate method for the evaluation of students. Thus the present study was aimed to evaluation the clinical knowledge and practice of the nursing students before entering to the clinical field by OSCE method in Rafsanjan Nursing and Midwifery School in 2010.   Material and Methods: In this cross sectional study, in two consecutive days, knowledge and practice of the 39 nursing students before entering to the clinical field that entered to study by census method were examined in determined stations in nursing skill laboratory with use of relevant check lists. Total practical, scores in examined procedurs was 200 that was divided into three levels of weak (0-70), moderate (71-140) and good (141-200). Total knowledge scores was 32 that was divided into three levels of weak (0-10), moderate (11-21) and good (22-32). Data were analyzed using spss software .   Results: Our results showed that, total scores in examined procedurs was 132.38±19.17 out of 200 that could be considered as moderate on the basis of likert scales. The total knowledge's, scores was 18.23± 3.7 out of 32 that was moderate on the basis of likert scales . The maximum mean scores was belonged to writing of drug form, kardex, nursing report and ECG procedure . The minimum mean scores was belonged to tracheotomy saction and sondaj procedures.   Conclusion: According to the results obtained by OSCE method, we can realize both weak and potent points of students. In this method also condition and materials are similar for all students, thus, this reduces worries of students regarding clinical examinations. Therefore, we propose that the method of clinical evaluation requires to be changed to OSCE to achieve improved quality in education in nursing schools.