This study aims to investigate the attrition rate of EFL concrete and abstract vocabulary among continuing and non-continuing Iranian female and male English language learners across different proficiency levels. They are students of a University and majored in different fields (between 20 and 25 years old). There was no treatment in this study where the researcher compared two groups on the same variables. Hence, the design of the current study is an ex-post facto design.

A 40-item vocabulary test which varied across two proficiency levels are used to measure rate of vocabulary attrition as the instrument of this research. In the two stages, after an interval of three months, the students are taken the same tests. The results revealed that there was no significant difference between EFL attrition rate of abstract and concrete nouns among the continuing students across different proficiency levels. However, this hypothesis was rejected for the non-continuing learners at intermediate and advanced proficiency level.