The purpose of this nonequivalent, control group, pretest-posttest design study was to evaluate the effectiveness of leveled book programs on first-grade students' oral reading fluency rates and comprehension levels. This study was conducted over a 10-week time span with four first-grade classes. All of the students in each class were given a pretest to determine their current reading level, and then the classes were randomly placed into the treatment group, which used leveled books during independent reading time, or the controlled group, which used trade books selected by the students during independent reading time. Two individually administered assessments, Developmental Reading Assessment (DRA) and STAR Reading Assessment, were selected to compare students' oral reading fluency and comprehension levels pretest and posttest scores. After the data was collected, an ANCOVA was used to determine if there was a statistically significant difference between implementing leveled books and trade books. The results from the ANCOVA revealed that leveled books are effective in increasing student oral reading fluency and comprehension level of first grade students. [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.]