It caused mayhem when it arrived in Sydney last year, and now cult US burger chain In-N-Out is back to satisfy Sydney burger lovers.

The famous West Coast brand will have a pop-up in Sydney's Darlinghurst today from 11am for just for a few hours.

If last year's random appearance in Melbourne is anything to go by, expect massive queues and a long wait - as the burgers sold-out within 30 minutes - so best to get in quick.

Jimmy's Burgers posted about the surprise pop-up this morning, confirming Darlinghurst's Wood and Smoke on Stanley Street as the temporary burger joint location for today.

It's been two years since the LA fast-food legends set up shop at L'il Darlin (also in Darlo) and three years since they whipped together a few burgers at Surry Hills' Dead Ringer, so you can bet there's still people out there who haven't had a taste and will be desperate to find out what all the buzz is about.

Expect a one-burger-per-person policy, so don't risk being the burger waiter for your mates.

We assume In-N-Out will stick to their basic hamburger, regular cheeseburgers and the double-double (double meat, double cheese).