This study aims to reveal the effect of the gamified response system, Kahoot!, on attitude towards the EFL course, motivation, and exam anxiety. For this purpose, an embedded mixed design, in which quantitative and qualitative methods are used together, was preferred. The study group consists of 88 ninth-grade vocational high school students. Before the experimental process, attitude, motivation, and exam anxiety scales were applied to the experimental and control groups as pre-tests. At the end of the experiment, attitude, motivation, and exam anxiety scales were conducted as post-tests to the experimental and control groups. In addition, the views of randomly selected students from the experimental group on Kahoot! application was examined. The results revealed that Kahoot! significantly increased the attitude towards the EFL course with a 0.22 effect size. Kahoot! increased EFL learning motivation and decreased exam anxiety, but this was not significant. Finally, it was revealed that the students thought Kahoot! as funny.