The current research was conducted with the aim of the effectiveness of group reality therapy on the students’ mental health and self-esteem. The research population includes all the PNU students, Karaj branch who were studying in the educational year of 2014-2015. In this research 40 students were selected through the random sampling method available as the research sample volume. Here, 20 students were selected through random sampling method available as the research sample volume that participated in the group reality therapy and 20 more students were selected as the control group. The method applied in this research is semi empirical with two groups of experimental and control. The experimental group was placed under 9, 90 minute sessions of group reality therapy. To collect data the Goldberg 28 question general health questionnaire and the Copper Smith 58 question self-esteem questionnaire were used. To analyze data, the descriptive statistics (average, standard deviation,…) as well as inferential statistics (covariance analysis) were applied. Results indicated that the average mental health scores in the experimental group's posttest are lower than that of the posttest in the control group. Also, the average self-esteem scores in the experimental group's posttest are higher than that of the posttest in the control group. It is, thus, concluded that group reality therapy is influential in promoting the mental health and selfesteem of the students..