This study aimed to investigate the effectiveness of a group counseling program based on the Theory of Multiple Intelligences in the Career-self development of grade nine students in the Al Dakhiliya Governorate in Oman. The study covers a sample of 60 male and female students of which (n=30) of them were in the experimental group, and the other (n=30) were as the control group. The experimental group experienced the group counseling program, while the control group have not received any counseling program. Quasi-experimental design was used in this study the Career-Self Concept scale was developed to the participants. The Career-Self Concept Scale consisted of 51 statements, and the reliability coefficient was 0.7. The results of the Two-ways ANOVA analysis showed that there were significant differences in the posttest between the control and experimental groups. The results of the study also showed that there were no significant differences in the Career-Self concept perception between the male and female students. Furthermore, the results of the t-test analysis for the interrelated groups, showed statistical significant differences in the pre and the post test for the experimental group for the post test. The results showed that there are no significant differences in the level of post test and follow up test which indicated the effectiveness of the program developed.