A method for detecting the blockage of a gasoline vapor filter (3) bleed valve (4) for a motor vehicle internal combustion engine (1), includes at least one sequence of the following steps: a step of controlling the opening of the bleed valve (4), a step of measuring at least one operating parameter of the internal combustion engine (1), which is related to the mixture taken into the engine, a step of calculating an indicator, via statistical signal-processing on at least one measured parameter, and of comparing the indicator to a predetermined value. A detection device capable of implementing the method is described.