Athletes must first qualify through the system or regulation set up by the international federation. Different sport has different methods to be qualified. Some are according to the continental or world ranking, while some sports have specific competitions, such as world championship or continental championship, that are used to select top athletes. Mixed models are often the case, and wildcard spots might be available.

No matter what the case is, each international federation has the ultimate decision to make sure the best of the best are to participate in the World Games 2009 Kaohsiung. International Federation Passport outlines the quota of athletes within each sport. Qualification details are available from each international sport federation.