For a long time the work of sport psychology was despised in the public opinion and eyed suspiciously. Very often sport psychologists were defamed and associated with deficiencies. However the image has changed in the past few years and decades. Many athletes vouch for sport psychology in public and appreciate its scientific techniques; hence, it could be described as a booming business. The present thesis wants to provide a detailed analysis of sport psychology and its techniques in competitive sports. The aim of this thesis is to create a compilation of scientific facts, combined with a digression into applied sport psychology.Based on necessary definitions there will be an introduction to the current methods of sport psychology. On this occasion the following topics will be explained: motivation and mental strength, visualisation, mental training, arousal regulation, how to handle emotions and stress in a competition, self-talk and causal attributions. Founded on these theoretical explanations, applied sport psychology, respectively golf, boxing, wrestling and sport shooting, as well as the mechanisms how sport psychology can assert itself in concrete sports will be examined.At the end of this thesis it should be comprehensible, why sport psychology is of such great benefit ? not only, but especially ? for competitive athletes and why sport psychological techniques are of utmost importance for success.