On the eve of World Cat Day, a new pop-up Sydney cafe is hoping to re-home dozens of kittens in Sydney's CBD this week.

Sydney Cat Cafe is partnering with animal welfare charity Maggie's Rescue to foster cats at the cafe and those interested will have the option of adopting them.

The pop-up in Clarence Street in Sydney's CBD is open this Friday and Saturday and will open again on August 13 to 15.

The cafe's first pop-up in Paddington in May saw 13 of 20 cats adopted over four days.

"My sister came back from Japan a few years ago and told me about this fantastic concept, and I thought, what a great way to marry two passions of mine and to open a cat cafe right here in Sydney," said Veronica Morland, the owner of the cafe.

"I think cat lovers come in all different shapes and sizes so we've had men, women, kids, you get groups of girls coming in squealing, and then you get a couple of beefy guys coming in also squealing and it's just a lot of fun for everybody."

The cats are specially selected for the cafe environment.

A cat enjoys itself at pop-up Sydney Cat Cafe. ( ABC News: Thuy Ong )

Veronica Morland is a lawyer by day and runs the business on the side, something she hopes to do full-time when the permanent cafe opens later in the year.

She said the cafe was a way to connect rescue cats with loving homes.

"The kittens we have in this room range from soft and cuddly little guys through to some playful little devils who just roll around on the floor all day, and then they're just out like a light," Ms Morland said.

According to Maggie's Rescue, Australia has the second highest pet euthanasia rates in the world with around 200,000 pets put down every year because they have no where to go.

"It's a wonderful platform for Maggie's rescue to showcase our animals, our cats for adoption, to get them permanent homes," said Justine Francis, a volunteer with Maggie's Rescue.

The cafe raised over $18,000 through crowdfunding platform Kickstarter in June.

"That kind of inner-city living...you can lose touch with having a pet, so lots of people who come in are cat lovers who can't necessarily own one," said Ms Morland.

Student and cat-lover Nicole attended an afternoon session.

"If it were permanent, I'd make it a permanent part of my weekly schedule," she said.

"It's so good to drop in and grab a coffee."

Another patron, Rebecca, tickling a black kitten said she "could never stop playing with cats".