This is the nerve-wracking moment a snake slithered into a toll booth, sending a collector running for her life.

The woman was sitting inside the payment kiosk when the viper appeared on the windowsill in Chengdu, China.

CCTV footage shows the employee checking her screen as the serpent slowly climbed toward the open window behind her on May 10.

She glanced at her notebook, unaware the reptile had moved next to her seat.

Moments later, she turned her head and spotted the snake, prompting her to scream and flee the booth.

The frantic collector then slammed the door behind her as the snake dropped onto the chair.

Wildlife experts say the region is home to two species of venomous viper and at least five nonvenomous constrictors, including rat snakes and wolf snakes.