How effective is the Social Skills Development Program on the self-concept, self-esteem, and social ability of shy adolescents needs to be determined. furthermore, the study investigated whether factors such as gender and academic achievement affect the self-concept, self-esteem, and social ability of shy adolescents. Subjects of the study, were 32 students randomly selected from a group 120 high school students of Colegio del Sagrado Corazon de Jesus noted behaviorally as ashy by their advisers. The study was conducted on January 28, 29, February, 2, 4, and 5, 1995. Data needed for this investigation used three standardized tools: Self-Concept Test (Everly,1979), Coopersmith Self- Esteem Inventory (Coopersmith, 1967), and the Social Ability Questionnaire (Berent, 1993). The study utilized descriptive statistical tools such as means and standard deviations. Inferential statistical tools such as t-test for independent samples, t-test for correlated samples, analysis of variance, and Pearson r set at .05 for two-tailed tests were used. Before the training, the subjects generally manifested moderate self-concept, except the excellent achievers who had weak self-concept. Pre-training self-esteem among the subjects was generally average. As to social ability, all the subjects reflected medium pre-training social ability. After the training, the subjects generally revealed strong self-concept. Post-training self- esteem among the subjects was average high in general. Even after the training, however, the subjects remained to have medium social ability in general. /the sole poor achiever among the subjects surprisingly revealed a high post-training social ability. Classified as to gender and academic achievement, the subjects did not differ significantly in their pre-taining self-concept, self-esteem, and social ability. Similarly, grouped according to gender and academic achievement, the subjects, likewise, did not differ significantly in their post-training self-concept, self-esteem, and social ability. The post-training self-concept of the subjects in all categories was significantly better than their pre-training self-concept as it moved from moderate to high. Meanwhile, the post- training self-esteem of the subjects as an entire group and that of the males, females, and those with satisfactory academic achievement was significantly better that their pre-training self-esteem as it improved from average middle t average high. The subjects under the other categories did not manifest any significant difference in their pre- training and post-training self-esteem. Finally, the post-training social ability of the subjects in all categories was significantly more desirable than their pre-training social ability. Significant positive correlations were observed in the following cases as reflected by obtained 2- tailed probabilities that were lower than the set significance level of .05 for 2-tailed tests: between pre- training self-esteem and pre-training social ability (p=.019), between pre-training social ability and post- training social ability (p=.012), beween post-training self-esteem and post-training social ability (p=.005). On the other hand, significant negative correlations were observed in the following cases as reflected by obtained 2- tailed probabilities that were lower than the set significance level of .05 for 2-tailed tests: between pre- training self-concept and pre-training self-esteem (p=.014), between pre-training self-concept and pre training social ability (p=.000), between post-training self-concept and post-training self-esteem (p=.014), between post-training self-concept and post-training social ability (p=.001). Adolescents involved in this study had problems with shyness arising from a low sense of self, lack of feelings of worth and confidence, and lack of some skills of social interaction. Indeed, the 5-day Social Skills Development Program was successful in bringing about significant changes on the shy adolescents self-concept, self-esteem, and social ability.