Paul Vaughan has stepped down from his post as chief executive of England Rugby 2015 by mutual consent.
Vaughan had been in charge of ER 2015 - the company set up to deliver the 2015 Rugby World Cup - since January 2011.
A short statement announced Vaughan's departure and said a new chief executive would be appointed shortly.
ER 2015 chairman Andy Cosslett said: "Paul has been at the heart of the RFU for the past 11 years, most recently here as CEO of ER 2015, where he has laid some very strong foundations.
"We are grateful to him for all the hard work he and his team have put in to enable ER 2015 to be ready for the next phase.
"Preparations have been continuing at a good pace, the planning is completely on schedule and stakeholders are comfortable.
"With just over three years to go, now is a good time to add a fresh injection of experience to take us up to the next level.
"We are determined to make the most of this once in a generation opportunity for rugby in this country, to make this truly the best Rugby World Cup there has ever been."