The present study investigated the effect of input enhancement on the acquisition of English politeness strategies by intermediate EFL learners. Two groups of freshman English majors were randomly assigned to the experimental (enhanced input) group and the control (mere exposure) group. Initially, a TOEFL test and a discourse completion test (DCT) ensured homogeneity of the groups in terms of general proficiency and pragmatic competence. Then, the participants received the instructional treatments on English politeness strategies (PSs). They read and listened to dialogues containing the intended PSs. The target PSs were in bold typeface in enhanced input group’s dialogue booklet and in regular font in mere exposure group’s booklet. Subsequently, the groups took the DCT posttest. The analysis of the pretest and posttest data revealed the following results: Iranian intermediate EFL learners differed from English native speakers in their use of PSs; there was a low relationship, an insignificant correlation (rxy = .25), between general proficiency and pragmatic competence (i.e. competence in English PSs) of Iranian intermediate EFL learners; and input enhancement had a significantly greater effect on the acquisition of English politeness strategies (both comprehension and use of PSs) than simple exposure to PSs. The study implies that EFL learners should be provided with a specific instruction on English PSs and PSs should be presented in a noticeable way (e.g. typographically enhanced).