Background: In education and learning, teaching to write well is still one of the challenges of Iranian English teachers. Objectives Since the writing skill has different aspects, this study aimed at investigating the impact of metalinguistic feedback and electronic feedback on the correct use of English prepositions in Iranian learners’ writings. Methods: The study utilized a semi-experimental design. The participants of the study were 84 Iranian language learners. These learners were randomly divided into one control and two experimental groups to take a writing pretest. One of the experimental groups received electronic feedback while the other was exposed to metalinguistic feedback. After the treatment period, the participants took a writing posttest. The writing products of the learners at both pretest and posttest were evaluated and scored in terms of the correct use of prepositions. The scores were analyzed through a combination of statistical tests of Kruskal-Wallis and Mann-Whitney. Results: The results of the Mann-Whitney test on the gained scores (posttests-pretest) of the three groups indicated that there was a significant difference between the sets of scores (H = 50.82, P = 0.00). Nevertheless, the result of Mann-Whitney U test showed that there was no significant difference between electronic and metalinguistic feedback (U = 433.500, P = 0.642), which means both types of electronic and metalinguistic feedback were equally effective on the correct use of English prepositions. Conclusions: In conclusion, the study led to a better understanding of the impact of electronic and metalinguistic feedback on the writing skill, which provided a basis for English as a foreign language (EFL) teachers to integrate them in the teaching and learning process.