There were 12 places originally allocated to continental associations in the tournament not already directly qualified to the Olympics – 5 from Europe, 3 from the Americas, 2 from Asia, 1 from Africa, and 1 from Oceania.
Greece, Hungary, Russia and Spain qualified from the 2012 European Water Polo Championships and confirmed their attendance at the tournament.
Canada, Brazil and Cuba qualified from the 2011 Pan American Games, Canada and Brazil confirmed their attendance, but Cuba declined to participate and no other teams from the 2011 Pan American Games volunteered to take their place.
Kazakhstan and Japan qualified from the 2012 Asian Water Polo Championship, Kazakhstan confirmed their attendance, but Japan declined to participate and there were no other nations entered in the 2012 Asian Water Polo Championship to take their place.
There was an article written by a FINA press correspondent in Japan showing confusion around the qualification procedure from the Asian Championship, as the article states that the winners of the Asian Championship had advanced to this qualification tournament (in fact, they qualified directly for the Olympics) and that Japan could no longer get to the Olympics (in fact, according to FINA By-Laws, they were eligible for this tournament, and they did not apply).