Staff reported seeing the rodents at the BBC's west London base, which is currently being sold as the corporation moves operations to the newly-refurbished Broadcasting House in the capital and the BBC North complex in Salford.
Speaking to the Daily Mail, a source said that working conditions at Television Centre are becoming "increasingly squalid" as staff are due to leave the base soon so bosses are "not bothering to carry out repairs".
The source added: "We're not sure exactly how many [rats] there are. They keep popping up at different places around the office.
"Probably the main thing attracting them is the fact that people are so busy they eat at their desks and there are crumbs everywhere."
However, BBC workers have seen the funny side of the situation, which follows last year's mice outbreak, including one leaving a fake rat on the desk of John Humphrys, the veteran host of the Today programme.
Rod Liddle, the former Today editor, told the Mail: "It was a far more civilised regime in my day - we just had mice, lice and fleas.
"Once, when I was on a train from Wiltshire to work, a flea actually hopped off me and on to the table in front of two other commuters.
"But rats are pretty heavy duty. I mean, you don't mess with a rat. I think they should set John Humphrys on them."
> BBC director general Mark Thompson to step down this autumn