The 35-year-old New Zealander signed a new 12-month deal a year ago after shelving plans to hang up his boots and has now been given a rolling contract, which means he can play on until either party decides the time is right for him to finish.
Leuluai, a five-time Grand Final winner who made his 200th appearance for the Rhinos in last Friday's 42-22 win at Bradford, signed his new deal on the eve of his side's Tetley's Challenge Cup fifth-round tie against Huddersfield.
"I am really pleased to have got the deal sorted and can now look forward to the future, starting with a big game against Huddersfield on Saturday," he said.
"You are a long time retired and it was a big decision for me. I have to thank my wife and family for their support to stay here in Leeds and carry on playing.
"I am feeling good and want to continue as long as I can and I am very grateful to the club for allowing me to do that."
Leuluai is nine months younger than team-mate Jamie Peacock, the former England captain who is playing on next year, and Leeds coach Brian McDermott is delighted with the announcement.
"Kylie has been in great form for us this season so it was a pretty easy decision to offer him a new deal once he decided he wanted to postpone his retirement," McDermott said.
"He is a leader within our team and works hard with our medical and conditioning staff to make sure he is in the best possible shape on game day.
"It is a big boost for the team to have Kylie back on board for next season and beyond."
- Sports & Recreation