The Rangers star damaged his anterior cruciate ligament against Aberdeen at the weekend.
A Rangers statement confirmed: “Scans have confirmed Steven Naismith sustained an anterior cruciate ligament injury to his right knee during Saturday’s game against Aberdeen at Pittodrie and he will sadly miss the rest of the season.
“Steven will be seen by the same surgeon who successfully treated him in 2008 and his rehabilitation programme will be eight to nine months.”
Rangers manager Ally McCoist told the club’s official website: “This is devastating news for Steven and our thoughts are with him. He was in the form of his life and it is a huge blow for him and the club that he is out for the rest of the season.
“He will get the best treatment possible in the weeks and months ahead and everyone at Rangers Football Club will support him during his rehabilitation period.
“Naisy has recovered from a serious knee injury before and he will come back again. He is a fighter and a popular member of the squad and we will all work hard to win games for him while he is out.”