Background and Aim: Dysmenorrhea is a common cause of reduced performance in the workplace, education, and reduced quality of life for women. The aim of this study was to evaluate the prevalence and factors associated with dysmenorrhea.The purpose of this study was to detect the prevalence of dysmenorrhea among students. Materials and Methods: This study was cross-sectional. The number of students (n=310) of Kashan. University of Medical Sciences that no pelvic mass, uterine cancer, and ovarian cyst surgery were randomly selected. And were selected randomly by a statistical software spss18 information were analyzed. Findings: The result of this study showed that from 310 students the 206 students % 66.5 have dysmenorrhea. Also, the start of menarche age and age average for dysmenorrhea were 13.6 and 15.6 respectively. From 206 dysmenorrhea 124 students % 60.19 had a history of dysmenorrhea pain in mothers and Among 176 with dysmenorrhea who were sister,number 128 students % 72/7 had a history of menstrual pain in Sister. The data analysis indicated that significant between dysmenorrhea and history of dysmenorrhea pain in mothers pv=0.02 and sister pv=0.01 there. Results: According to the results of this study High prevalence of dysmenorrhea among students. Students with education and awareness can reduce the severity of dysmenorrhea and reduce it.