Background: The aim of our research was to determine the contest effectiveness of Japanese judo competitors and to state the quantitative an qualitative indices of the tactical-technical preparation (PTT). The values of these indices may be used for controlling the process of special preparation.Material/Methods: Medal classification of the national teams from all Olympic Games and World Championships, and contest effectiveness of the national teams during 2007-2010 were determined. The analysis of PTT indices of 16 Japanese competitors was carried out. They fought 78 contests during the World Championships 2010. Predominant techniques were described. The selected indices have been assessed.Results: Japanese competitors prevailed over their opponents in the men's group during the Olympic Games and the World Championships. After changing sport rules in judo, they overcame their poor performance within 2007-2009, and they have become leaders in world's judo. Japanese competitors are highly effective in leg throws, especially in such throws as: uchimata, osoto gari, and kouchi gari as well as seoi nage (although this throw is a hand technique). They executed throws forwards and mainly by means of pivot. Japanese competitors had a positive value of activity indices and high indices of defense.Conclusions: Sport results achieved by Japanese judo competitors prove their high contest performance and the dominating position in judo competitions. Among their dominating techniques, we can see leg techniques performed by pivoting and breaking balance forwards on toes. They are also effective in executing grappling techniques such as holdings (immobilizations) for example. During the World Championships in 2010 Japanese competitors were characterized by a positive value of activity indices and high indices of defence.