The current study aims to assess the effect of a cognitive-behavioral counselling program that was built to improve the self-assertiveness for a sample of students of the Higher Technical College. The study population consisted of (7,311) students from the Higher Technical College, from all academic departments in Muscat Governorate in the Sultanate of Oman, and according to the college's statistics for the second semester for the academic year (2019/2020).The sample of the study consisted of (32) female students with various levels and departments in the Higher Technical College; who scored lowest grades in Rathus Scale for Self-Assertiveness. The selection process was carried out in two stages; the first stage has been restricted to the female students who need to improve their self–assertiveness, and volunteered to participate this study, the total number reached (100) students. In the second stage, the sample was selected based on statistical analyzes and included the (32) students from the prior stage, who have a low level of the self-assertiveness, then the sample was randomly distributed into two groups; experimental group and control group, each of them had (16) students. The group counselling program was done based on CBT. The program had been implemented within (6) weeks, with an average of two sessions per week. The duration of each session is (90) minutes.The results showed that there were statistically significant differences at (0.001) between the control group (who did not receive any training) and the experimental group (who received the training program) in the post measurement. The mean value for the experimental group was higher than it for the control group; which indicated the effectiveness of the training program.In addition, the results indicated that there are significant differences between post measurement and tract measurement within the experimental group in the self-assertiveness scores. The results demonstrated that the applied program is effectual in improving the self-assertiveness among the study sample.Furthermore, several recommendations and proposals were presented based on these results.