Accommodation priced in the thousands has all but sold out as teenagers scramble for a room for next month's school leaver celebrations.
The official school leaver hubs in Dunsborough and on Rottnest are almost fully booked, with about 9000 Year 12s expected to party from November 25 to 28.
Of the 4300 accommodation spots available to leavers in Busselton, about 1000 places remain, many of them camping spots.
Up to 8000 teenagers are expected to flock to the South West - about 500 more than last year.
Leavers project acting manager Scott Bermingham said about 1200 were expected to celebrate on Rottnest, where about 90 per cent of the accommodation had sold out.
Accommodation for the three nights can cost thousands. A cabin on Rottnest during the celebration costs between $1230 for a six-bed berth and $3104 for eight beds for three nights, as well as a $2000 bond.
In the South West, a powered campsite for up to four people at Four Seasons Holiday Resort in Busselton costs $1200 during the event and a two-bedroom villa at Amalfi Resort in Busselton costs $2160, as well as a $2000 bond.
Organisers have warned they will turn away anyone who turns up on Rottnest without accommodation booked and have strict rules for those staying in the South West.
"If you don't have accommodation, your parents could be called," Mr Bermingham said. "We don't want kids staying on the streets."
Beachlands Holiday Park owner Gavin Farrell said that apart from campsites, the entire site had been booked for the event by April.
The park will be closed to the general public and extra security will be brought in for the celebration.
Leavers' week was a major event for tourism providers, Mr Farrell said. "They're bringing a lot of money into our community and there's a lot of businesses that do exceptionally well out of it," he said.