The primary purpose of this study was to investigate the combined and partial effects of the Integrated Reading/Study Strategy and Conceptual Physics Approach on ninth grade private high school students' achievement in and attitudes toward optics. The Integrated Reading/Study Strategy is a new strategy which was developed by integrating previously existing reading strategies of the KWL and SQ3R with classroom lecturing. The Conceptual Physics Approach is an instructional strategy developed on the basis of Conceptual Physics suggested by Paul G. Hewitt. To investigate the partial and combined effects of methods, factorial design was used. The study was conducted with 124 students from two private high schools in the Cankaya district region of Ankara, Turkey. Various teaching/learning materials were developed and used for the study. Two measuring tools, Achievement Test about Optics and Attitude Scale about Optics were used as pre and post tests before and after instruction. The study continued for a two-month treatment period. The results of the study showed that the combined effect of the Integrated Reading/Study Strategy and Conceptual Physics Approach improved students' achievement significantly compared to the separate individual methods. Although the product of the Integrated Reading/Study Strategy and Conceptual Physics Approach increased students' attitudes more compared to the remaining methods, the result is not statistically significant.