Despite the complex nature of writing, many students are hesitant to tackle difficult subjects. To help those facing writing difficulties and increase their motivation, this study examines the effect of teacher-student collaboration through guided-writing instruction. A two-group quasi-experimental design was used with a pre-treatment-post-tests format. The participants in this study were 50 11th-grade students (aged 17–24; 28 male and 22 female) from Data Sana Memorial School in Wolaita Sodo City, South Ethiopia. Writing skill tests and questionnaires about writing motivation were used to collect data, which was then analyzed using independent smples t-test analysis to determine the effectiveness of guided-writing on students’ writing improvement and motivation. Although the pre-test results did not show a significant difference between the mean scores of the control and experimental groups, the post-test results of the writing skill tests showed a statistically significant difference between the means of the experimental and control groups. Additionally, the results of the writing motivation questionnaires revealed that the mean score of the experimental group increased significantly in the post-test compared to the pre-test. These findings demonstrate the usefulness of guided-writing instruction in assisting students with writing difficulties and motivation. In conclusion, the findings have implications for teaching writing through guided-writing instruction and it is recommended to help students struggling with writing and a lack of motivation. Moreover, further research into writing instruction through guided-writing in various ecological aspects and grade levels is required.