Abstract: This study was an attempt to identify the nature of the ego identity for the high and low-achieving students in secondary schools in Qaseem region, the Kingdom of Saudi Arabia, to reveal the level of these students' psychological hardiness, and to examine the relationship between the ego identity and psychological hardiness. Moreover, this research seeked to identify the differences in the ego identity in terms of achievement, grade, age, and the family size. A descriptive method is used in this study (survey, correlational, discriminative). The study population is secondary school students in Qaseem region during the school year 2011-2012 (N=9931) divided into three secondary classes: first, second and third. The sample consists of 500 students, randomly selected; 5 students from each grade. Two instruments are used in this study: The Ego Identity Questionnaire including 5 areas of Abo Baqr Morsi (2001), and Psychological Hardiness Questionnaire including 3 areas of Emad M. Mekhaimar (2011). Results indicated that secondary school students in Qaseem region in Saudi Arabia possess a moderate level of the ego identity crisis reaching (56.3%). The highest component of the ego identity crisis for the participants is making relationships with the other sex (69.5%), independence and individualism (60.1%), accomplishment and goal direction (54.8), playing social roles (52.1%), and finally making life meaningful and philosophical (56.3%). Results indicate a statistically significant, negative correlational relationship (0.01) between the ego identity and psychological hardiness (r=- .509). The results of regression analysis show that the components of the ego identity accounts for 34% of variance in psychological hardiness. Moreover, there is a statistically significant, positive correlational relationship between achievement and psychological hardiness, whereas there is a statistically significant, negative correlational relationship between age and psychological hardiness. There are statistically significant differences at the 0.001 level in the ego identity attributed to achievement variable, in favour of good and very good. There are no differences in the total score on the Ego Identity Questionnaire for the variables of grade and the family size.