There is a growing tendency among the researchers about how to assess and improve the ability of speaking. In spite of its complex nature, speaking is generally considered to be the most essential skill to acquire. With the onset of communicative language teaching, this inclination has encouraged researchers to carry out research and make recommendations and implications. This study aims to improve the speaking abilities of EFL students at prep school by using online videos at Osmaniye Korkut Ata University. The study was carried out with 20 low level students in 5 classes in an English Language prep class at Osmaniye Korkut Ata University in Turkey. Of 20 students ten were chosen for the treatment group. These students were selected in accordance with the results of the first speaking exam administered in the 2015-2016 academic year. The materials used were five videos available online. The researchers asked the students to watch five videos respectively within the period of five weeks. These online videos were taken from YouTube, BBC, VOA and TED. The data were analyzed by using t-test in terms of the results of second speaking exam and gender. Results show that those who watched videos improved their speaking ability and scored high than those who didn't, and in view of gender, the girls were more successful than the boys. Thus, it can be concluded that using online videos in classes can be of vital importance and effective in improving EFL learners' speaking ability. [This study was presented as a proposal in the 9th ELT Research Conference, 12-14 May 2016, Çanakkale, Turkey.]