This study attempts to investigate the relationship between EFL learners’ knowledge of near synonyms and their performance on a corpus-driven test of collocational behaviour. Near synonyms are defined here as lexical pairs that have very similar cognitive or denotative meanings (e.g. powerful and strong), but may differ in collocational behavior (strong tea but powerful car). The study is based on a random sampling of subjects (N= 60) drawn from a pool of 200 EFL learners taking English classes at different language institutes in Khorramabad, Iran. To elicit the data, two types of tests: a Near Synonym Test (NST) and a Collocational Behavior Test (CBT), were constructed, validated, and used. The items for both tests were mainly selected from COBUILD Dictionary. Pearson-Product Correlation was applied to measure the relationship between the specified variables. The results showed that there is a significant relationship between EFL learners’ knowledge of near synonyms and their Performance on the corpus-driven test of collocational behavior. The implications of the findings for language pedagogy are discussed
