This study was an attempt to investigate the relationship between Iranian EFL learners' multiple intelligences (MI) and incidental vocabulary learning. The study was conducted in classes of two institutes in Tehran. The participants of the study were 42 Iranian female intermediate EFL learners, selected based on the score that they got on the Nation's Vocabulary Levels Test, and by taking this test, the learners' vocabularies proficiency level were homogenized. Then MIDAS questionnaire investigating eight types of different intelligences was used in this study. In the next stage, a vocabulary pretest which was designed by the researcher and was piloted in the same condition to the main study was conducted prior to the treatment of the study (extensive reading program).when the treatment of the study finished an immediate vocabulary posttest conducted to the same participants. The vocabulary posttest was exactly the same as vocabulary pretest. The results of the study showed that there was a significant relationship between Iranian EFL learners' MI and incidental vocabulary learning and also among the eight different types of intelligences; there was a significant relationship between naturalist and incidental vocabulary learning.