And Rangers assistant manager Ally McCoist was pleased they could secure Naismith for the next five years.
"I'm absolutely thrilled. Steven's a great kid and this season he's come on leaps and bounds," said McCoist.
"It's a real boost to the club that he's decided to extend to 2015. He's had a tough time, getting a serious knee injury in a game at Hampden.
"It's tough when he had to watch the boys training while he's in the gym.
"But he's a great worker and personally I'm delighted he's signed, but also with the way he's playing."
In previous seasons Naismith's appearances had also been limited by the prowess in front of goal of his former Rugby Park team-mate Kris Boyd and the availability of other strikers such as Nacho Novo.
But this season Naismith's fine form and injuries to new arrivals Nikica Jelavic and James Beattie have seen him prosper.
Ibrox defender Steven Whittaker also welcomed Naismith's decision to sign a new deal
"He's shown this season what an important player he is for us and it's great he's committed his future to Rangers," said Whittaker.
Bookmark with:
What are these?