Background: This study was undertaken to determine the prevalence of psychological stress among Isfahan medical sciences students.Methods: Cross-sectional, questionnaire-based survey was carried out among the 387 medical sciences students (medicine, pharmacy, and dentistry) of Isfahan, Iran through census. In academic year 2010–2011, Kessler-10 questionnaire was given to the students a month before semester examinations. Scores ³20 were considered as indicative of positive stress symptoms.Results: The overall prevalence of stress among medical sciences students was found to be about 76.1%. The prevalence of stress among medicine students was 22.7% mild, 23% moderate and 21.4% severe while 32.8% showed no stress. The prevalence of stress among pharmacy students was 22.22%, 22.22%, 26.19%, and 29.36% mild, moderate, and severe and no stress, respectively. The prevalence of stress among dentistry students was 25% mild, 27% moderate, and 10% severe while 37.5% showed no stress. The prevalence of stress was higher (70.6%) in pharmacy students when compared with medicine (66.1%) and dentistry (62.5%) students. The odds of student having stress is higher in dentistry students (OR: 1.44, P= 0.33), where as the odds are decreasing in pharmacy student (OR: 1.16, P= 0.66). There is no statistically significant association between gender, ages, and term and having stress symptoms.Conclusions: The high level of stress necessitates interventions like social and psychological support to improve the student’s well-being. A prospective study is needed to study the association of psychological morbidity with sources of stress and coping strategies.