In this study, the importance of vocabulary knowledge in language education and the use of mobile applications in the teaching of collocations are emphasized. The application of collocation was realized through a mobile instant messaging application. It has been determined that students use a mobile application in a word learning process to provide more meaningful learning than in classroom learning. In this study, which was applied to 54 people using experimental and controls grouped research design, the experimental group was given mobile cards and the control group was given word cards in the class. In quantitative aspect, the study aimed to see the difference between the academic achievements of both group. At the end of the process, an academic achievement test was applied to the students, and a significant difference was found between the groups in favor of the experimental group. In qualitative aspect, the students opinions was given on use of mobile applications in teaching vocabulary. Individual interviews were conducted with the students at the end of the process accordingly and these interviews were used in the evaluation of the process.