A method and a system for detecting the first signs of malfunction of an aircraft engine valve, including an acquisition device to acquire the output pressure measurements of the valve, and contextual and command data of the valve, a processor to define a set of indicators of the first signs of malfunction, according to the output pressure measurements and the contextual and command data. A set of estimators corresponding to the set of indicators of the first signs of a malfunction, is determined using a previously produced regression model. At least one distance between the set of indicators and the set of estimators is computed. The distance is compared to a threshold of the first signs of a malfunction, in order to detect the first signs of malfunction of the said valve.