The placebo effect is a well-known phenomenon in various areas of science, but little is known about its history and mechanisms that are in its background. A few studies suggest the importance of the motivational component in the background of the placebo effect. In the area of sports psychology, motivational construct self-talk is used in most sports to stimulate motivation and improve sports performance. The aim of the study was to determine contributions of placebo effect and self-talk in sports performance. The participants in the study were 80 college students from the University of Zagreb and Catholic University of Croatia. Participants had to perform a medium-hard psychical exercise (wall sit) before and after treatment implementation, and they were sorted into one of four groups: control, placebo, self-talk or placebo and self-talk. They also had to fill a Questionnaire on self-perception of sports skills and status that was constructed for the purpose of this study. The results of the analysis show a significant impact of the placebo effect and self-talk on an individual’s sports performance, meaning that the individual’s sports performance improved after treatment implementation. Furthermore, the results show that the group that was under the influence of placebo effect and self-talk showed the biggest improvement in their sports performance after receiving treatment. The results of this study provide a good basis for future studies and show that every individual that is affected by placebo and self-talk has an untouched potential that can improve his sports performance.