This article focuses on the use of smartphones inside the EFL classrooms in order to improve English vocabulary acquisition and to promote learner autonomy. It aims at determining the successes and drawbacks of integrating smart-phones inside the EFL classrooms and analyzing the learning outcomes, the learners’ awareness, responsibility and autonomy. For this purpose, 20 EFL learners took part in the investigation. The participants were randomly selected from the University of Badji Mokhtar, Algeria. A well-designed questionnaire has been designed for learners to study their perceptions towards the use of smart-phones while learning new English vocabulary. For more accuracy, an interview has been established with 10 teachers to investigate their attitudes towards the use of smart-phones in vocabulary acquisition and promoting learner autonomy. This paper seeks to find out how the use of smart-phones might improve English vocabulary acquisition and foster learners autonomy. The findings indicate that smart-phones use improves and assists vocabulary acquisition and develops learners autonomy and responsibility over their own learning process.