That figure comes after more than 8 million copies of the browser were distributed in its first 24 hours of availability.
Of the 19 million downloads, 5.48 million were performed in the US. Germany was second, with 1.7 million, followed by Japans 1 million downloads and the UK, with 807,900 copies of Firefox downloaded.
Mozilla kicked off the Firefox 3 campaign with an effort to set a new Guiness world record for most downloads in a 24 hour period. The event was almost too successful, as user nearly knocked out Mozilla's servers in the early hours of availability.
The day closed with over 8 million copies of the new browser downloaded worldwide. The company said that it is still waiting to hear back from Guiness judges regarding verification of the record.
However, the Firefox 3 release may already be reaping an even larger reward for Mozilla. A company spokesperson told vnunet.com that the browser's market share had climbed from 18.41 per cent in May to 19.17 per cent by the end of last week, citing data from research firm Net Applications.