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.