The 40-year-old reality star - who has kids Mason, nine, Penelope, seven, and four-year-old Reign with her ex Scott Disick - is keen to spend more time with her children, so she will not appear on the forthcoming 18th series as much.
She said: "I just decided to spend more time as a mom and put more of my energy there.
"But I'm not saying goodbye ... I think you'll have to see more of it on the new season, season 18.
"It isn't airing yet, but it's being filmed. Currently, in this room."
Kourtney's sister Khloe Kardashian admits she will miss not seeing her sibling on the show as much, but is confident she will "come back".
She said: "We definitely love Kourtney and we will miss Kourtney and whatever she decides to do, but people come, people go all the time in this family.
"We feel like it's a revolving door, so Kourtney might leave this week, she'll be back. They all come back."
And the pair's sister Kim Kardashian West joked that Kourtney taking a back seat could pave the way for another 'KUWTK' spin-off alongside Khloe.
Speaking in a joint interview on 'Entertainment Tonight', she added: "Like, just Kim and Khloe take ... Calabasas. "That'd be amazing. We can live in the condo with all of our kids and see how that goes."
In May, Kourtney hinted she may move away from the US altogether at some point.
She said: "I always say I want to move away someday and just be away from it all.
"Sail away. No one will ever see me again.
"I keep throwing up different places, but then I'll go there to visit and I'll be like, 'Nope, this isn't it, but glad I came.'
"We've just been to Finland. And I was like, 'Check, it's great for me to visit, but I'm not going to move there.' Maybe Norway. Switzerland? I've got a lot of ideas."