This study investigated the impact of semantic clustering on Iranian EFL learners’ vocabulary retention at advanced level. Participants were female learners randomly assigned to two groups of 15. Four instruments (TOEFL test; vocabulary pretest; immediate posttest, and delayed recall posttest) were used. The experimental group underwent semantic clustering vocabulary presentation in which the learners were provided with six lists each containing ten semantically related words in sentences, while, the control group was provided with the same words but the sentences were presented in a random way containing different topics, not semantic groups. The results revealed the outperformance of the control group in the delayed recall posttest.
