It extends BBC Sport's current deal, which runs until 2013, as exclusive broadcaster of the Six Nations and covers TV, radio and online.
This year's tournament saw audiences increase to their highest level for 13 years, with an average audience of 4.7m per match.
"The Six Nations is a crown jewel in the sporting calendar," said BBC director of sport Barbara Slater.
The championship, the premier annual northern hemisphere rugby union tournament, is contested by England, Ireland, Scotland, Wales, France and Italy every February and March.
"We're delighted that we can continue to bring the tournament to our audiences," Slater added.
"Viewing figures continue to grow year on year and we look forward to continuing to work in partnership with the Six Nations to build interest even further through the BBC's unparalleled offering of TV, radio, online and interactive services."
In total over 30m people within Britain watched some of this year's tournament.
Among the most memorable matches in the 2011 edition were Italy securing a first ever Six Nations win over France and England, who had won their first four matches, being denied the Grand Slam when they lost to Ireland.
John Feehan, chief executive of the Six Nations, added: "We are delighted that BBC Sport will maintain, extend and enhance its coverage of the RBS Six Nations, the world's biggest annual rugby tournament, for a further four years to March 2017."

Jamie Stevenson's entry, which incorporates a saltire, their black and white colours and their nickname - The Honest Men, won 48% of the votes.
The Scottish Championship club were forced to find a new crest as their old one broke ancient heraldic law.
Designs were whittled down to a shortlist of five that were voted on by the public.
Commercial manager Graeme Miller told his club website: "Nobody wanted to change our badge.
"However, when left with no option, I think the route we chose to take has been a hugely positively one.
"We visited numerous local schools with our players and mascot Pandamonium and the response from the kids was incredible.
"Hundreds of entries were sent in from local youngsters and hopefully the excitement generated when we visited them will have given them an interest in the club for the future."
Winning designer Stevenson, who has lived in Peru for five years, attended his first Ayr match in 1979 and went on to design the club's match-day programme.
A badge containing an anchor, representing Ayr's proximity to the sea, came second with 25%.
The new badge will be adopted from 1 July.

The man, who was 31, was shot by police on Francis Street at around 09:35 GMT. A Taser was also used.
The IPCC said officers had fired more than one shot at the man.
Humberside Police said armed officers had been sent to the Holderness Road area at about 09:20 GMT following reports of a man carrying an axe.
More on this and other Hull stories
The IPCC, which is investigating the shooting, said: "At this stage, the IPCC understands that officers fired more than one shot at the man, at around 09:35 on Francis Street.
"During the incident a Taser was also discharged by police."
The dead man has not been named but his family have been informed, it added.
Earlier Humberside Police confirmed it had been responding to calls from members of the public and confirmed the force was not looking for any other individuals in connection with the incident.
One builder working nearby said he heard gunshots.
"I heard two fires, that's all I heard really," he said.
"It was scary, a scary situation."
Rachael, who was attending a training course in a nearby building, said she heard two "loud bangs and screaming".
"Then we looked out the window and he was laid on the floor," she said.
"He had what looked like two large sort of cuts, slashes things low down and there was blood coming out of them.
"There were about four or six (police officers) with him on the floor and he was trying to sit up, obviously he was bleeding quite a lot."

3 March 2017 Last updated at 09:09 GMT
It's a big problem - it's estimated that 1.2 million people aged 16 to 25 in England have at some point stayed in an unsecure or unsafe place.
Actor Connor Lawson, who plays Alex, and Gaia Marcus, from the homelessness charity Centrepoint, join Jenny on the sofa to talk about it.
You can watch the show to find out what is in store for Alex.
The BBC has agreed a deal to broadcast the Six Nations until 2017.
[NEXT_CONCEPT]
An Ayr United fan living in Peru has designed the winner of an online poll to choose a new club badge.
[NEXT_CONCEPT]
A man shot by police officers in Hull has died in hospital, the Independent Police Complaints Commission (IPCC) watchdog has said.
[NEXT_CONCEPT]
CBBC drama series The Dumping Ground is focusing on the issue of homelessness through a new character called Alex.