A failure information system that transmits various kinds of failure information of a vehicle to an outside diagnosis service center is disclosed. The failure information system includes a signal receiving unit that receives a signal indicating a failure of a vehicle-mounted system, a vehicle-run judging unit that judges that the vehicle is running, a run-distance calculation unit that calculates a run-distance of the vehicle since the signal indicating a failure is received, a reliability judging unit that judges that the signal indicating a failure is reliable if the signal receiving unit continuously receives the signal indicating a failure until the run-distance exceeds a preset distance level, and an over-vehicle communication unit that transmits the failure information that includes the signal indicating a failure when the reliability judging means judges that the signal indicating a failure is reliable.