The Cardiff Blues prop made his international debut against Romania in 2002 and has played a part in four RBS 6 Nations titles, including three Grand Slams.
Jenkins has also been selected on three British & Irish Lions tours, winning a further five international caps.
And members of the Wales management and playing squad have been quick to heap the praise on the 32-year-old.
"He had a phenomenal game last week in terms of work-rate. I think he is a sensational player. His kick-chase was pretty good last week, he defends and in his own way is a leader on the park.
"His body seems to be holding together. He has dropped four or five kgs and he is looking really fit at the moment. He has been training hard.
"It is a fantastic milestone for someone who has been a great servant of Welsh rugby. I hope we can go out there on Saturday and give a performance that reflects his contribution to Welsh rugby, we play well and win."
"He's a phenomenal athlete. Let's not forget what he does at our set-pieces. Not only does he have ability around the field, in attack and defence, he jackals on the ball and is a very astute rugby player.
"His mum would be very, very proud of him completing his 100 caps on Saturday. I know he's family man and I'm sure there'll be someone smiling looking down when he runs out on Saturday.
"He's a unique man. Gethin as a player has the utmost respect from everyone, players and coaches.
"To get to 100 games in the front row is remarkable. I feel tired after one game let alone 100. To come through all that and still be on top form...
"He is one of the most professional guys I have ever come across. If you are doing something wrong he'll tell you straight, he won't mess around.
"But you need that sometimes from your leaders, your senior boys to say 'look, wise-up, this is how we're going to do it'.
"It's deserved that he gets 100 caps this weekend.
"He's a good guy - sometimes he doesn't come across that way to some of you.
"His leadership skills are second to none. Sometimes he plays the game like an outside-half!
"For him to get 100 caps is a great achievement, for him and his family. He's been consistently good throughout his career. His work-rate on the field is huge and he's a massive role model for young kids.
"Gethin's an exceptional player who has been on three Lions tours and he's won Grand Slams with Wales. He has been a top player for his country for about ten years now and I'm really pleased for him, his family and everyone who knows him.
"He's set the bar as a modern day prop. His tackling, he's coming out at nine and smashing people, has great hands and has set standards for the props coming through behind him. He deserves to reach 100 and I'm chuffed for him."
WALES' MOST CAPPED PLAYERS
Stephen Jones - 110 (Wales 104 + Lions 6)
Gethin Jenkins - 104 (Wales 99 + Lions 5)
Martyn Williams - 104 (Wales 100 + Lions 4)
Gareth Thomas - 103 (Wales 100 + Lions 3)
Adam Jones - 94 (Wales 89 + Lions 5)