Objective <p>This quasi-experimental study aimed to compare the effectiveness of lecture-based teaching with three corpus-assisted methods—concordancing, collocation, and frequency—in promoting retention of medical terminology among English as a foreign language (EFL) medical students at Iran University of Medical Sciences. The study evaluated short- and long-term retention of eight cardiovascular terms using the Vocabulary Levels Test conducted at three intervals over a month.</p> Results <p>Forty EFL medical students were divided into four groups (<i>n</i> = 10 each) and taught the target medical terms using either lecture-based or corpus-assisted methods. Pre-test Vocabulary Knowledge Scale scores showed no significant baseline differences. Results of post-tests showed frequency analysis showed the highest mean score of immediate retention (7.3 ± 0.5), followed by concordancing, collocation, and lecture-based methods. At two weeks, concordancing led (7.0 ± 0.8), followed by frequency, collocation, and lecture-based methods. At one month, concordancing maintained the lead (6.6 ± 0.8), followed by frequency (6.2 ± 0.9), collocation (5.0 ± 1.0), and lecture-based (2.7 ± 1.2). Corpus-assisted methods outperformed lecture-based teaching across all intervals, with concordancing showing the strongest long-term retention.</p>