Background: Patient education is taken into account as one of the key components of comprehensive care as well as one of the significant nursing functions in order to increase community health. In this respect, education materials and written texts can improve patient information up to 50% and consequently meet patient satisfaction. Readability is considered as an integral concept in patient education and an appropriate measure to determine how contents are perceived by readers. Aim: The present study was to measuring the readability level of patient education pamphlets in training hospitals in the city of Mashhad. Method: This study was a descriptive research conducted in 2016. In order to measure the readability level, the Simple Measure of Gobbledygook (SMOG) Readability Test was used. The study sample included 543 patient education pamphlets used by 11 training hospitals in the city of Mashhad along with pamphlets developed by the Office of Vice-Chancellor for Treatment Affairs that were collected through the census method. The SPSS16 software was also employed for data analysis. In terms of descriptive analysis, mean and standard deviation were used. In addition, Cronbach’s alpha correlation test was employed for inferential analysis. Results: The average readability level of patient education pamphlets was estimated equivalent to 11th grade (11.35±1.05). Moreover, the minimum and the maximum readability levels of the pamphlets were 9th grade and 15th grade, respectively. Implications for Practice: The results revealed that patient education pamphlets available in training hospitals in the city of Mashhad were endowed with a high level of readability. Thus, the given pamphlets were appropriate to patients with a level of literacy equal to senior university students and they could not be perceived by the public. Considering the importance of readability index in health promotion and increased patient self-care, it was recommended to improve the readability level of patient education materials.