Research has established a strong relationship between silent reading comprehension and prosodic reading fluency among young readers, but much remains unknown about this relationship among older readers (Breen, Kaswer, Van Dyke, Krivokapic, & Landi, 2016; Cypert & Petro, 2019). The goal of this study was to determine the impact of prosodic reading instruction on adolescents' silent reading comprehension. Conducted in a classroom setting in two different school districts, this study included three certified English teachers and a total of 52 students in grades 8, 9, and 10 for a period of nine to twelve weeks with a total of 810 instructional minutes. The Fluency Development Lesson (FDL) (Kuhn, Rasinski, & Zimmerman, 2014; Morrison & Wilcox, 2020) structure provided the format of instruction for the treatment variable, prosodic reading instruction. District-selected digital standardized assessments provided pre- and post-treatment silent reading comprehension scores to assess the impact of the treatment on silent reading. Using SAS software, the researcher used a repeated measure analysis of variance (RMANOVA) to test the impact of the treatment. Regarding silent reading comprehension, analysis revealed an effect size of 2.3%, indicating that the treatment produced no significant impact. To assess students' prosodic reading, the EARS rubric (Rasinski & Cheesman-Smith, 2018), a multidimensional fluency scale, provided pre- and post-scores for which analysis showed an effect size of 36%, a significant impact. The results of this study are inconsistent with recent research which shows that as prosodic reading scores increase, silent reading scores increase (Wolters, Kim, & Szura, 2020). This inconsistency may be attributed to the lack of clarity involved in measuring specific aspects of prosody (Morrison & Wilcox, 2020; Wolters, Kim, & Szura, 2020). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]