http://www.istc.org/sisp/index.htm?f...event_id=51104 Says there the night parade attracts over 500,000 people...
http://en.wikipedia.org/wiki/Fiesta_Week No specific numbers but it does say the battle of flowers is the second largest parade. I've heard that numerous times. I'm too lazy to look for more stuff but i've always heard that the attendance numbers for both those parades are in the 250,000+ range