Since English pronunciation errors by Persian speakers are often caused by the transfer of the Persian language sound system, the present study investigated the effect of explicit pronunciation instruction on undergraduate English as a Foreign Language (EFL) learners' vowel perception enhancement. The nonequivalent group, pretest-posttest design was employed to study two classes of English literature and English teaching students at Kosar University of Bojnord (KUB) as the experimental group (EG) and control group (CG), respectively. A 40-item minimal pair test was developed based on the 3rd edition of the book Ship or Sheep: An Intermediate Pronunciation Course written by Baker (2006). The reliability of the test was estimated 0.75 through KR-21 formula. After the pretest administration, both groups were exposed to the same activities; however, only the EG received the treatment regarding explicit pronunciation instruction. At the end of an eight-week training program, the pretest was used as the posttest. The results of the independent samples t-test from the posttest revealed that the EG had a better performance than the CG, suggesting that EFL learners' vowel perception can improve if they are explicitly made aware of their pronunciation errors.