Over the past decades, studies of EFL/ESL vocabulary acquisition have identified the significance of collocations in language learning. Due to the fact that collocations have been regarded as one of the major concerns of both EFL teachers and learners for many years, the present study attempts to shed light on the impact of corpus-based collocation on EFL learners' collocation learning and awareness. 60 Iranian EFL learners, who participated in this study, were chosen randomly based on their scores in an OPT exam. There were two groups, experimental and control ones. The study examined the effects of direct corpus-based collocation instruction on EFL learners' collocation learning. For 15 sessions the control group received single-item vocabulary or, the usual work of their class and the experimental group received lexical collocation instruction as treatment. The same test as post-test was given to the learners when the treatment accomplished, and after that a t-test and kolmogorov-smirnov test between the pre-tests and post-tests were calculated. According to the results demonstrated by the statistical program, the effectiveness of the treatment was noticeable. This study suggests that direct corpus-based collocation instruction can be a worthy alternative. It demonstrated that the learners, who were in the experimental group, got aware of the existence of collocations, used them and learnt them properly, and they also started to find the collocation of every other word, which they learnt during the term, by themselves because the treatment appealed to them.