for any educational program to be successful, many factors work hand in hand. based on pervious efl studies, teachers and learners are the keys to gain achievement. granted the fact that explicit and implicit practice plays a key role in education, knowledge of it can help teachers facilitate students’ vocabulary learning. this study investigated to determine the contribution of explicit and implicit practice on expanding of breadth and depth of vocabulary knowledge. at first, the pre-test was given, in order to make sure the participants were at the same level of english proficiency, aged from 17 to 37.the participants took the nelson english language proficiency test and 60 of them were selected out of the pole of ninety. the participants were randomly assigned in two groups at the beginning of the course. the pre test distributed into two groups, and the data were collected .one of the groups was taught through implicit instruction and another one by explicit instruction. after ten sessions of instruction, the same test as post test was performed for two groups and the data were collected and analyzed by the appropriate statistical analysis. this study revealed that, the implicit practice had a better effect on breadth and depth of vocabulary knowledge. key terms: explicit practice, implicit practice, breadth of vocabulary, depth of vocabulary, efl learners.