The purpose of this study was to explore the effects of text modification on the reading comprehension achievements and reading motivation of general secondary school students in Ethiopia. Drawing on input processing and cognitive theories, the researcher hypothesized that text modification would enhance both students' reading comprehension and their motivation to engage with reading. A quasi-experimental design with a pre-test and post-test comparison group was employed to examine this hypothesis. The study involved 105 Grade 10 students from three sections at Fasilo General Secondary School in Bahir Dar, Ethiopia, during the first semester of the 2023 academic year. The participants were divided into three groups: a simplified text group, an elaborated text group, and a control group, each consisting of 35 students. Over the course of 16 weeks, the experimental groups received modified texts either simplified or elaborated while the control group worked with unmodified, baseline texts. The study aimed to assess whether these modifications would have a significant impact on students’ reading comprehension and reading motivation. Data were collected using reading comprehension tests, a reading motivation questionnaire, and interviews with participants. Statistical analysis using one-way ANOVA was conducted to examine differences in reading comprehension achievements and motivation between the groups, with the significance level set at p<0.05. The results indicated that there were no significant differences between the three groups in terms of their pre-test reading comprehension and reading motivation scores. However, after the 16 week intervention, the experimental groups, both simplified and elaborated text groups significantly outperformed the control group on both the reading comprehension post-test and the post-reading motivation questionnaire, with p-values less than 0.05. The results of the study suggest that educators and language instructors can benefit from incorporating text modification into their teaching practices to enhance student outcomes in reading comprehension and motivation. Furthermore, the study's findings can contribute to curriculum development and instructional design in language education. Future research can build on these findings by exploring the impact of text modification on other language skills, such as writing and speaking, and by examining the role of teacher professional development in implementing text modification strategies.