The invention relates to the field of monitoring and aid to taxiing of an aircraft at an airport.The invention is a method of checking and monitoring the taxi plan and relates to a monitoring system comprising means for checking the pathway of the plan and means for signalling on the taxi aid the waiting time for the next clearance ahead of the aircraft along the pathway, the means for checking the pathway comprising a device for checking the pathway constraints and a device for checking the clearances, the device for checking the constraints making it possible to test and to display on the taxi plan the information descriptive of the constraints and the device for checking the clearances making it possible to check the clearances and to add the missing clearances to the taxi plan.