There will 272 people working for the corporation at the tournament this summer, fewer than the 295 who travelled to South Africa in 2010.
BBC Sport director Barbara Slater said her "aspiration" was to make Brazil 2014 "the first 24/7 World Cup".
Writing in a BBC blog, she said she aimed to deliver more hours of coverage than in the last World Cup for "less than the cost of a pint of milk for each viewer, listener or website user".
She said: "With over 9,000 kilometres between BBC Sport's HQ in the UK and our production teams in Brazil, it is technically very challenging to leave significant elements of the broadcast operation back in the UK.
"For example, the significant delay in communications between the two countries presents an unacceptable risk to the continuity and quality of our programmes if we attempted to control the live operation from back in the UK with commentators, cameras and presentation teams spread around Brazil."
There will be 12 separate commentary teams working on TV and radio covering 31 live matches as well as shows including a documentary about David Beckham travelling to the Amazon rainforest.