Lexical bundles are referred to as the groups of words which often occur together in a language. They are considered as a category of word combinations and are words that follow each other more frequently than expected. To this aim, the present study has attempted to investigate the effects of accelerated learning and explicit instruction on the retention and application of lexical bundles in Iranian intermediate EFL learners’ writing skill. Thus, a pre-test was administered to 87 language learners out of whom 60 male and female language learners were selected and randomly divided into two experimental groups of 30. One of the experimental groups was taught the lexical bundles in writing through explicit instruction. As for the other, the teacher played some music in the classroom to give the class an effective atmosphere in learning the lexical bundles. The experiment lasted for 9 weeks. The results of the study revealed that the two groups performed differently on the posttest, showing the fact that the accelerated learning of lexical bundles did enhance EFL learners writing ability. However, it should be stated that other studies revealed the effectiveness of the explicit instruction of lexical bundles to improve the writing skills of language learners (e.g. Biber, Conrad, & Cortes, 2004).