With the impact of globalization and advanced digital technology, the ways students learn have changed remarkably through the decades. Therefore, the skills that students today should acquire from schools are not limited merely to the subject knowledge. Learners need to be equipped with the skills of the era commonly known as the 21 st century skills. To address such need, this research project was conducted to implement Project-Based Learning (PBL) with a group of EFL learners at the Demonstration School of Prince of Songkla University. Two main purposes were to examine students' levels of motivation to learn English through PBL and to investigate the learner's perception of the impact of the PBL on improving their 21 st century skills, namely, collaboration and communication. Findings from the survey suggested that PBL is perceived to be effective in promoting the Vol. 13 No. 2 (2018) 159 JSEL Vol.13 No.2 2018 learner's motivation to learn English. Furthermore, PBL can enhance the target 21 st century skills which are essential for the learners to succeed in learning as well as for work in the current age. Therefore, PBL is suitable for the participating language learners and can be worth-implementing in other EFL classrooms in Thai high schools.