This research sought to study the academic self-concept and the relationship between the academic self-concept and students' academic achievement among university Qatari students. Research of the academic self-concept is well documented in Western cultures, but the academic self-concept research is limited among Qatari students. A sample composed of 274 undergraduate university students was utilized in this study. Tools of data collection consisted of demographic characteristics such as gender and age; students' cumulative Grade Point Average (GPA) as academic achievement; and the Academic Self-concept Questionnaire (Byrne, 1996) to measure the academic self-concept, which was composed of 40 items, distributed in 4 subscales namely Maths, Verbal, Academic, and Problem Solving. The result of the study revealed a significant but weak relationship between the academic self-concept and the academic achievement.