The head of the BBC, George Entwistle, has left his job after big mistakes were made in a news story.
Mr Entwistle had only been Director General for eight weeks.
He decided to leave after one of the BBC's most famous news programmes, Newsnight, made big mistakes in a report, on November 2.
As his job involved being responsible for everything that's broadcast by the BBC, Mr Entwistle said he felt he had to resign.
One of the most important things about the BBC is that many people feel they can trust that the information they hear on programmes and read about online is correct.
But earlier this month, the Newsnight programme made a big mistake in one of its stories, wrongly suggesting that a senior politician from the 1980s had committed a serious crime.
This caused a big row, with Newsnight having to say sorry live on air last Friday.
On Monday, other bosses in BBC News were also asked to step down from their jobs while investigations take place to try and find out how things went so badly wrong.