Four fire crews were at the scene and a helicopter was brought in as access was difficult, said northern fire communications shift manager Steve Smith.
Police have cordoned off the area and the surrounding roads at the Arikikapakapa golf course in Whakarewarewa, 3km south of Rotorua.
The course has helped produce Danny Lee, the first New Zealander to win the US Amateur Championship in 2008.
Don Blackledge, golf course manager, said golfers had been asked to move away from the area, but it had not affected play on the course.
"I'm not sure how big an area it is. We haven't evacuated anyone, but we're just keeping people away from the area. It's in scrub, it's not in an area where there are people.
"There's a lot of smoke and we've got the helicopter here at the moment pouring water on it," Mr Blackledge told NZPA.
Meanwhile, eight fire crews were battling a scrub fire near Cornwallis Beach, 31km south-west of Auckland, at the corner of Huia Rd and Pine Rd.
The fire broke out at 12.20pm and had spread over two hectares, but it was not close to any buildings.
"We haven't had to evacuate anyone as it's right in the bush," Mr Smith said.
A helicopter was on standby.
