English language teaching has newly been introduced to pre-school curriculum in Turkey. The purpose of this study was to investigate the effectiveness of teaching EFL vocabulary to pre-school children through Project Based Learning (PBL). For this purpose, an experimental design, consisted of observation checklists, exam scores and a short survey, was adopted. Firstly, through a short online survey, 150 kindergarten teachers were asked to specify which techniques they commonly used in their English classes. The primary aim here was to define traditional techniques and the rate of PBL use in Turkey. After defining common techniques, 28 children were randomly assigned to experimental (PBL instruction) and control groups (traditional instruction) equally and the data was collected in real time classroom setting for 8 weeks. The results showed that (1) PBL was rarely adopted in EFL classes in Turkey, (2) PBL instruction could increase EFL vocabulary learning gains when compared to common methods and (3) young learners were observed to have been more active in PBL classes. The effect of PBL instruction was discussed in local, cognitive and motivational perspectives in the light of previous related research. The potential benefits of further PBL use for young EFL learners and implications were also discussed.