Southland co-coach Culhane was finally confirmed as the new Highlanders assistant coach last night.
He joins former All Black team-mate and Wellington coach Jamie Joseph, replacing Glenn Moore and Peter Russell.
"It's pretty exciting," Culhane said.
"I am delighted to be joining the team. Southland is a proud provincial union partner of the Highlanders franchise, so this is a natural progression for me. I'm looking forward to the challenge."
Culhane (42), a backs coach, has guided Southland for the past five years with forwards coach David Henderson.
The Stags were second-bottom in the national championship the year before Culhane and Henderson arrived.
They steadily improved under the new coaching duo, reached the semifinals in 2008 and 2009, and won the Ranfurly Shield for the first time in 50 years.
"Southland probably wasn't going as well as we would have liked at the time," Culhane said.
"I guess the Highlanders, if we're brutally honest, haven't been going as well as we would like. There are some similarities there."
There was speculation Culhane had been reluctant to seek a role at Super 15 level, but he said he had business and family commitments to consider.
He will be based in Dunedin for a large chunk of the year, and will be doing a lot of commuting as he settles into his role.
Culhane, who played six tests for the All Blacks, is well aware of Joseph and his coaching style.
"I've coached against him a few times now. Unfortunately I haven't been able to beat him yet. I suppose if you can't beat him, you join him.
"He came down for the big match at the weekend and stayed at home with us. I'm pretty comfortable that we'll get on well as a coaching team."
Culhane will take up his Highlanders role immediately, but unlike head coach Joseph - who relinquishes his Wellington job after this weekend - he is allowed to continue in his provincial role.
Bryce Woodward, who applied for the Highlanders head coaching job, was named a Blues assistant coach yesterday.
