This quasi-experimental study aimed to investigate the effect of polite corrective feedback (CF) on Iranian EFL learners’ immediate and delayed grammatical accuracy. The participants included a convenient sample of 60 intermediate male/female EFL learners (four 15-member groups) selected from a private language institute in Tabriz. After the researcher ensured the homogeneity of the participants, a researcher-made multiple-choice pre-test on present and past English tenses was administered. Later, the first and second experimental groups were treated with +Polite Explicit Feedback (in the form of elicitations) and +Polite Implicit CF (in the form of recasts), respectively while the control groups were provided with –Polite Feedback of the same forms. Following the assessment of the learners' oral grammatical accuracy immediately after the treatment (uptake), a multiple-choice post-test was administered two weeks after the immediate post-test to assess their delayed recall. The independent samples t-test and ANCOVA conducted on the pre-test, immediate learning scores, and delayed post-test scores indicated that, although polite CF in both groups had a significant effect on learners' grammatical accuracy, +Polite Explicit Feedback had a more significant effect on participants' performance than –Polite Explicit Feedback and +Polite Implicit Feedback. The results underscore the significance of integrating POLITENESS element into CF discourse, bearing implications for educational planners, materials developers, and EFL instructors.