The 29-year-old prop decided enough was enough after an injury marred 2011 NRL season and recently told club coach Anthony Griffin he would hang up the boots to concentrate on his career as a physiotherapist.
Kenny's loss, on top of the mid-season retirement of fellow prop Shane Tronc, has stripped the Broncos of a combined total of 225 NRL games, but the return of club favourite Petero Civoniceva from the Penrith Panthers has balanced the books.
The Broncos also have Kangaroos Test prop Ben Hannant and former Melbourne Storm grand final prop Scott Anderson to help show the way for youngsters Josh McGuire, Mitchell Dodds, David Hala and Dunamis Lui.
He was voted the Broncos' most improved player in 2008 and was clubman of the year in 2009.
"Nick was a very hard worker who got the most out of his body," Broncos coach Anthony Griffin said yesterday.
"He could certainly hit and 2009 was undoubtedly his best season when he made the Australian train-on squad.
"He was a quiet guy, but a great worker off the field with charities and community organisations.
"He had a year to run on his contract but decided to call it quits and we wish him well."