A vehicle dispatch service system that provides a vehicle dispatch service in which a vehicle is dispatched to a user to arrive at a hospital at an appointment time of the hospital includes: an arrival time calculation unit that calculates a time at which the vehicle is estimated to arrive at the hospital as an estimated arrival time; an arrival estimation unit that acquires the estimated arrival time from the arrival time calculation unit and estimates whether the user is in time for the appointment time of the hospital; a rebooking unit that resets, when the arrival estimation unit estimates that the user is not in time for the appointment time, a new appointment time as the appointment time based on the estimated arrival time; and rebooking output unit that outputs the new appointment time to a predetermined output destination such that the user recognizes the new appointment time.