The aims of this study is to assess the level of self esteem among adolescent and determine the effectiveness of Bibliotherapy. Background of the study: Low self-esteem in adolescents aged 12 to 15 can lead to friendship difficulties, feelings of victimization, loneliness, avoidance of new experiences, and a struggle with failure. Bibliotherapy, involving specific text reading, offers therapeutic support, helping teenagers overcome these challenges by creating strong connections and transporting them to different times and places through reading. Objectives: To assess the pretest and post-test level of self-esteem among adolescents. To evaluate the effectiveness of Bibliotherapy by comparing the pre and post-test levels of self-esteem among adolescents. To determine the association between the pretest level of self-esteem among adolescents with their selected demographic variables. Conceptual framework: The conceptual framework adopted for the study was based on Modified Kenny’s Open System model. Materials and Methods: A quantitative research study was done. A quasi-experimental study, one-group pretest, posttest design was adopted for the present study. Sample: The accessible population for the study consists of high school adolescents. The study was conducted in St. Paul’s Inter College Shahjahanpur, U.P. The sample size was 50, selected by non-probability purposive sampling technique. Data Collection: Data was collected using the self-esteem structured inventory scale. The data was organized in a master data sheet and analyzed using descriptive and inferential statistics as per the objectives of the study using SPSS, version20 software. Results: The pre and post-test self-esteem scores among adolescents indicate that at pre-test, the mean self-esteem score and SD was 38.06 ± 4.191, whereas at posttest, it was 67.94 ± 5.815. The obtained t & p value for the pretest was t = 33.177, p = 0.0001. The t-test revealed that there was a significant difference within both the groups at pretest and posttest scores. Thus, it can be interpreted that the posttest has rapidly improved the level of self-esteem compared to the pretest. It shows that Bibliotherapy was effective in improving the level of self-esteem among adolescents.