Zahra Jamshidi - MA students, Department of English Language Teaching, Shahreza Azad University, Shahreza, Isfahan, Iran
Mehdi Ghaedrahmat - PhD student, Department of English Language Teaching, Faculty of letters and Humanities, Urmia Univeristy, Iran.
Faeze Shahdostfard - phD student, Ilam Univeristy, Iran.

This study set out to investigate the possible effect of phonological clustering on vocabulary learning and retention of intermediate EFL learners. To this end, 54 pre-intermediate EFL learners were selected though an OPT and a vocabulary pre-test. Wesche and Paribakht's (1996) Vocabulary Knowledge Scale (VKS), was run among the participants, to find out if they were at the same level of vocabulary knowledge. Each participant was tested on four categories that consisted of sets of five words that were phonologically similar or not. Participants were given Persian words and were asked to produce the written L2 English equivalent. 30 target words were presented during three sessions. After the treatment a post test was run and two weeks later a delayed post-test was run. The results revealed that phonological clustering can enhance vocabulary learning among EFL learners; however, long term retention of vocabulary cannot be guaranteed by phonological clustering technique. Key words: phonological clustering, vocabulary acquisition, vocabulary knowledge, EFL learners.