This dissertation aimes to determining the effectiveness of the proposed group counseling program to reduce the psychological stress in the client mothers who frequentise Al-Wafa Social Center for the Rehabilitation of Disabled Children in AL-Mudhaibi. In addition, it investigates the effectiveness in reducing the stress level among those mothers, changing some of the negative ideas and misconceptions associated with disability and turning them into positive ideas. Methodology: The study invloved 120 particiapnts of client mothers and a number of 64 of their mentally-challanged childern whose disability is ranging from mild to moderate to severe. This group represrents a comprehensive purposive sample. A psychometric stress scale was applied to 20 mothers of the mentally retarded children and were divided into two groups; Expermintal and Controlled. The expermintal one consists of 10 mothers and underwent a training program of 11 sessions over two months, which means two sessions per week for 120 minutes. It was concerned with the impact of the group program as an independent variable to reduce the psychological stress as a dependent variable. To achieve this goal, a group counseling program was developed, and a psychometric stress scale was applied to the participating mothers as pre-test, post-test and follow-up test. To examine and answer the hypotheses of the study, a T-Test was carried out to compare all tests, and find out the averages and standard deviations of the psychological stress levels in both groups on these three measurements. Furthermore, ETA Squared and the Mann-Whitney U Test were used to examine the effect size. Conclusion: The results indicated that there were statistically significant differences at (α≤0.05) in reducing the psychological stress in favor of the experimental group. The counsling program also provided the members with many techniques that were unknown to them, and contributed well to reduce the levels of psychological pressure. Moreover, the results showed that there were no differences in the experimental group's psychometric stress scale among the post and the follow-up scale, which was conducted one month after the program stopped. In the light of the findings, the researcher recommends that to apply the counsling program at the Al-Wafa'a Centers for the Rehabilitation of Disabled Children with different disabilities and also to benefit from this program to reduce the psychological stress of other groups who were not part of the study scope, such as divorcees and mothers of children who have been subjected to various types of abuse.