personality dimensions has impact on students performance. Therefore, in the present study evaluated the personality dimensions among Iranian female high school students. In a cross –sectional study, personality dimensions were investigated among high schools female students in Ilam (Iran) during the academic year 2014-15. A multistage cluster random sampling was utilized to choose the participants. Data were collected by two demographic and NEO Five-Factor Personality Inventory questionnaire. The Cronbach’s alpha coefficient was measured as an index of internal identicalness of the questionnaire to verify its reliability. A total 400 student were studied. The Mean ± SD of the personality dimensions were 24.27 ± 7.47, 16 ± 5.22, 21.22± 4.27, 23.9 ± 5.67 and 19.8 ± 5 for neuroticism, extraversion, openness to experience, agreeableness and conscientiousness personality dimensions respectively. There were significant relationship between all personality dimensions and students' average score for studying (P= 000). The results of this study demonstrate that about 20% of study participants have low flexibility, low agreeableness and low responsible personality.