This study aimed at investigating the influence of L1 (Turkish) on the acquisition of L2 (English) collocations by comparing the scores of two Turkish ELT student groups with a phrase-judgment test. The test included both congruent and incongruent collocations as well as unrelated word combinations. The participants whose vocabulary levels were defined as 3000-word level (low level) and 5000-word level (high level) according to Vocabulary Level Test (VLT), which was developed by Schmitt et al. (2001) were asked to judge whether the expressions were acceptable in English. The scores of the low-level and high-level students were compared in terms of their error rates and reaction times to the collocations. The overall results indicated that participants in both groups made more errors with incongruent collocations than congruent collocations. Their reaction times were also longer with incongruent collocations than with congruent collocations. However, the data yielded nonsignificant results in terms of the vocabulary levels of the participants for both error rates and reaction times.