: Corrective Feedback (CF) provision on performance involves calling attention to learners' erroneous utterances, which stimulates classroom language learning. Despite widespread research in this area, a controversy still exists as to the time of CF in communicative tasks especially when learners' task engagement is targeted. Employing 60 intermediate-level Iranian learners, a four-week study examined the effects of immediate versus delayed CF types on oral engagement, grammar gain as well as on Complexity, Accuracy and Fluency (CAF) in the context of a dictogloss task. The statistical analysis showed that despite statistically significant improvements in the case of Grammaticality Judgement Test (GJT) from the pre-test to the post-test, no statistically significant difference was found between the two groups with regard to their grammar gain, complexity, accuracy, fluency, as well as on their social and cognitive engagement. However, results in the case of behavioral and emotional engagement revealed that there were statistically significant differences between the two groups of immediate and delayed CFs. The findings of the present study call for more flexibility and confidence on the part of the teachers in providing either immediate or delayed CF whenever appropriate and without being concerned about the adverse effects of feedback
