The present study aimed at investigating the effect of using Skype on intermediate and advanced Iranian EFL learners' speaking. To this end, two groups of learners were homogenized and their speaking proficiency was evaluated through an IELTS speaking test. Afterward, intermediate and advanced learners were divided into two groups of experimental and control groups. Next, the control groups' participants were given specific topics to discuss. Furthermore, both experimental groups were taught speaking skill through Skype. At the end of the course, researchers administered IELTS speaking test to all groups. Next, a semi-structured interview including 3 questions was developed and was administered to the experimental groups in order to finding out the participants' attitude toward using technology in ELT classes. The results of two independent t-tests indicated that the experimental groups in both Advanced and Intermediate levels outperformed their counterparts in the control groups. Furthermore, based on the results of another independent t-test, it was concluded that the effect of using Skype on speaking proficiency of intermediate students was greater than that of advanced level students. Lastly, the results of the interview showed some positive and negative aspects of using Skype. Key words: technology, speaking proficiency, Skype, advanced EFL learners, intermediate EFL learners