Background and Objectives: This study sought to observe the effect of written feedback on the structural accuracy and writing mechanics of Iranian junior high school students’ assignments.
Methodology:A total of 57 students from three intact classes in two junior high schools, taught by the same teacher, were studied. Two classes were selected as experimental groups, while the third served as the control group. All three classes covered the same materials as outlined in the class textbook and were homogeneous in terms of gender, age, socio-economic status, as well as educational background. The researcher used nonparametric tests to analyze the results. To compare the performance of the three groups in pretests and posttests, the Kruskal-Wallis test was used. For further pairwise comparisons, the Mann-Whitney U test was applied. the SPSS21 was used to analyze the data. 
Results:The results revealed that, in terms of writing accuracy, the provision of teachers’ written feedback on students’ homework assignments is significantly more effective than general oral feedback. Moreover, the effectiveness of written feedback is considerably enhanced when combined with parental follow-up supervision.
Conclusion: The findings highlight that written feedback significantly improves writing accuracy more than oral feedback, with parental supervision further enhancing its effectiveness. Combining written feedback with parental follow-up is recommended for optimal student progress in writing.