A remote air conditioning start system includes a portable terminal of a user, a center server configured to communicate with the portable terminal, and a vehicle that includes an air conditioner and is configured to communicate with the center server. The remote air conditioning start system includes a user positional information acquisition unit, a vehicle positional information acquisition unit, and a controller. The user positional information acquisition unit is configured to acquire positional information of the portable terminal. The vehicle positional information acquisition unit is configured to acquire positional information of the vehicle. The controller is configured to perform control of the air conditioner including a start timing of the air conditioner based on a start request transmitted from the portable terminal to the center server according to a predetermined operation of the user based on the positional information of the portable terminal and the positional information of the vehicle.