"He's very disappointed that he can't fulfil the tour but it's nothing to be alarmed about.
"He's seeing his doctor now but he's still his lively self."
News of the procedure was issued in a statement by the company promoting the tour in Australia, Sir David Attenborough: A Life On Earth.
"Sir David Attenborough is to undergo surgery in London today following advice from his cardiologist that he is in urgent need of a pacemaker," Lateral Event Management said.
"It is with regret, therefore, that Lateral Events CEO Simon Baggs announced that the forthcoming sell-out tour of Australia, scheduled to begin in Brisbane next week, has been cancelled.
The company said it would discuss rescheduling the tour following the surgery, while BBC director of television Danny Cohen also sent a message of support, saying: "We all wish Sir David a full and strong recovery."
Sir David, whose groundbreaking programs have included Blue Planet and Frozen Planet, recently narrated and presented the hit BBC1 series Africa.
He also presented a new BBC Radio 4 series, Tweet Of The Day, devoted to birdsong.
The wildlife star said recently that he had no intention of doing less, saying: "I've been broadcasting for 60 years. I don't want to slow down. Retirement would be so boring."
- AAP