Abstarct: This study aimed to investigate the effects of integrating interactive mobile applications on vocabulary retention among Iraqi English as a Foreign Language (EFL) learners. Addressing the persistent challenge of vocabulary retention in the Iraqi educational context, where traditional rote-memorization methods predominate, the research sought to empirically test whether a structured, technology-enhanced approach could yield superior and more durable learning outcomes. Employing a quantitative, quasi-experimental design, the study involved two intact classes of intermediate-level university students in Baghdad. One group served as the experimental group, receiving vocabulary instruction integrated with applications like Quizlet and Memrise over an eight-week period, while the control group followed conventional textbook-baxsed methods. Data were collected through a researcher-constructed Vocabulary Knowledge Test administered as a pre-test, an immediate post-test, and a delayed post-test four weeks later. Additionally, engagement metrics (total time spent on the apps) were recorded for the experimental group. Statistical analyses, including independent and paired samples t-tests and Pearson correlation, were conducted to address the research questions. The findings revealed a statistically significant and large advantage for the experimental group over the control group in both short-term and long-term vocabulary retention. While both groups exhibited some forgetting over time, the experimental group retained a significantly greater portion of the learned vocabulary. Furthermore, a strong positive correlation was found between learners' engagement with the applications and their retention scores, indicating that higher usage was associated with better outcomes. The study concludes that a pedagogically structured integration of interactive mobile applications is a highly effective strategy for enhancing vocabulary retention in the Iraqi EFL context. The results validate the applicability of cognitive theories underpinning Mobile-Assisted Language Learning (MALL), such as spaced repetition and retrieval practice, within this specific setting, while highlighting learner engagement as a crucial mediating factor. The research provides evidence-baxsed recommendations for instructors, curriculum designers, and policymakers to modernize vocabulary instruction through guided technological integration, teacher training, and support for learner autonomy.