A method and a system are provided for detecting first signs of failure in an aircraft engine valve. The system includes an acquisition device configured to acquire output pressure measurements of the valve and command and context data related to the valve, and a processing device configured to define a set of indicators of first signs of failure as a function of the output pressure measurements and the command and context data. The processing device is configured to monitor a change over time in each indicator of the set of indicators of first signs of failure. The processing device is configured to detect a possible deviation of at least one indicator among the set of indicators, the deviation representing the first signs of failure of the valve.