The actress - who played Queen Vic landlady Peggy Mitchell for 16 years - will make an explosive comeback later this year in a special one off appearance.
Peggy returns to the Square from Portugal to help son Phil (Steve McFadden) after he gets himself into some serious bother.
A source told The Sun: “Peggy Mitchell is an EastEnders institution and a real fan favourite. Getting her back for an episode is guaranteed to pull in a huge number of viewers.
“Barbara still has a great relationship with everyone at the show, so when they approached her about coming back she was more than happy to oblige."
And it seems Barbara's return could pave the way for a permanent comeback.
The source added: “Since she left the Square Barbara has had a great time and kept herself busy, but she would not rule out making a long-term comeback at some point.
“She’s in no rush but she’s so popular with the viewers and so loved on set that it would make sense if she returned for good one day.”
Speaking about her comeback to the BBC, Barbara, 75, said: “It may only be a short visit, but it's a family matter and as Peggy always said 'it's all about family'.
"It is no secret how much I have always loved EastEnders and Peggy Mitchell - and by the number of times I'm constantly stopped by the great British public and asked either 'when are you coming back' or 'please say get out of my pub', it seems they have too," she said.
Since leaving 'EastEnders' Barbara has appeared in pantomime and presented a Radio 2 series on female comics.
Her return to the soap will coincide with old favourites Samantha Womack reprising her role as Ronnie Mitchell and Michael French returning as David Wicks.
Lorraine Newman, executive producer of 'EastEnders', said: "Peggy's surprise visit is a wonderful treat for our fans, as well as the cast and crew here on EastEnders. It's great to welcome her home," she said.