This study measured the impact of asynchronous computer-assisted language learning (CALL) approaches on high and low achievers' vocabulary retention and recall of English as foreign language learners. Fifty participants were assigned into two homogeneous groups. Both groups covered eight expository passages, which included "Select readings: Pre-intermediate and intermediate" course books developed by Bernard and Lee (Bernard, J., & Lee, L. (2004). "Select readings: Pre-intermediate." Oxford: Oxford University Press). Finally, they took the delayed post-test as an indicator for the long-term effect of the experience. The "t"-tests analyses revealed that the difference between the two groups was significant in terms of retaining vocabulary in immediate post-test (retention) and delayed one (recall); however, high achievers benefited from the CALL approach to learn vocabulary in both retention and recall processes, while the low achievers gained the chance of learning vocabulary just in retention period. However, their ability to recall vocabulary faded away after the time delayed since low achievers could not keep the recall abilities during the time lapses for more than two weeks (p less than 0.05). (Contains 6 tables.)