The "Read Naturally"[R] program is a supplemental reading program that aims to improve reading fluency, accuracy, and comprehension of elementary and middle school students using a combination of texts, audio CDs, and computer software. The program uses one of four products that share a common fluency-building strategy: "Read Naturally[R] Masters Edition", "Read Naturally[R] Encore", "Read Naturally[R] Software Edition", and "Read Naturally[R] Live". The common strategy includes: modeling of story reading, repeated reading of text for developing oral reading fluency, and systematic monitoring of student progress by teachers and the students themselves. Students work at their reading level, progress through the program at their own rate, and work (for the most part) on an independent basis. The program can be delivered in three ways: (1) students use audio CDs with hard-copy reading materials ("Read Naturally[R] Masters", "Read Naturally[R] Encore"), (2) students use the computer-based version ("Read Naturally[R] Software Edition"), or (3) students use the web-based version ("Read Naturally[R] Live"). This intervention report includes studies of "Read Naturally[R] Masters Edition" and "Read Naturally[R] Software Edition". The What Works Clearinghouse (WWC) identified 58 studies that investigated the effects of "Read Naturally"[R] on the reading skills of beginning readers. The WWC reviewed 11 of those studies against group design evidence standards. Four studies (Arvans, 2010; Christ & Davie, 2009; Hancock, 2002; Kemp, 2006) are randomized controlled trials that meet WWC evidence standards without reservations, and one study (Heistad, 2008) is a quasi-experimental design that meets WWC evidence standards with reservations. Those five studies are summarized in this report. Six studies do not meet WWC evidence standards. The remaining 47 studies do not meet WWC eligibility screens for review in this topic area. Appended Research details for Christ and Davie, 2009; (3) Research details for Hancock, 2002; (4) Research details for Kemp, 2006; (5) Research details for Heistad, 2008; (6) Outcome measures for each domain; (7) Findings included in the rating for the alphabetics domain; (8) Findings included in the rating for the reading fluency domain; (9) Findings included in the rating for the comprehension domain; (10) Findings included in the rating for the general reading achievement domain; (11) Supplemental subtest findings for the alphabetics domain; and (12) Supplemental subtest findings for the comprehension domain. A glossary of terms is included. (Contains 11 tables and 10 endnotes.)