In 1958, Tokyo was awarded the 1964 Olympic Games. The Japanese judo authorities sent a formal request to the IOC to include judo in the program of the 1964 Olympic Games. At the 1960 IOC Session in Roma, judo was approved for the 1964 Olympic Program, although only as an “optional sport,” at the discretion of the host nation. This was not understood at the time by the judo community.
The weight class question was decided in favor of weight classes. They had been held at the United States’ championships since the early 1950s and the European Championships made them standard in 1957. The Japanese had opposed weight categories but in 1962, Anton Geesink of the Netherlands won the World Championship in the open class in a dominating manner. The Japanese were now concerned that if only an open class were contested, they would be left with no judo titles, which was unthinkable to them. It was elected to use the European standard of a lightweight (<68 kg.), middleweight (80 kg.). Britain, France and Belgium pushed for the inclusion of an open class, and this became the fourth category.
The 1964 judo events took place in the Nippon Budokan – the Japanese Military Arts Hall. The matches were held on a traditional Japanese tatami, set in the center of the stadium. Preliminary round matches lasted 10 minutes, and the finals were 15 minutes. Most of the competitors had spent at least some time training in Japan. The exception was the Soviet team, which brought athletes who had converted to judo from the traditional Soviet jacket wrestling sport of sambo.
In each class, the athletes were separated into various round-robin pools. The winner of each pool qualified for the knock-out round, or effectively quarter-finals. From the pool winners, single-elimination bouts were held until a winner was determined in each class.