This study investigated the effects of comprehensive feedback on learners’ grammatical accuracy during text revision and in new writing tasks in light of proficiency level. It also sought to determine to what extent learners’ proficiency level plays a role in their feedback preferences and attitudes towards the feedback. The participants were 52 low proficiency and 39 high proficiency foreign language university learners, who were randomly assigned to a direct corrective feedback, a metalinguistic feedback with rule reminders, and a self-correction group. All learners wrote four compositions and completed a questionnaire after the treatment to elicit their attitudes towards the feedback and their feedback preferences. Results showed that the treatment effectively enhanced both low and high proficiency learners’ immediate grammatical accuracy and accuracy improvement. Also, a relation between proficiency level and learners’ attitudes towards the feedback as well as an association between proficiency level and learners’ feedback preferences were found.