Abstract: The system for assisting the regeneration of depollution means (4) associated with oxidation catalyst-forming means (3) integrated in an exhaust line (2) of a motor vehicle diesel engine (1) in which the engine (1) is associated with common manifold means (5) for feeding fuel to its cylinders, the system being adapted implement, at constant torque, a strategy of regeneration by injecting fuel into the cylinders of the engine in at least one post-injection, is characterized in that it includes means (7, 8, 9) for detecting a stage in which the vehicle engine is idling or in which the accelerator pedal is being raised, and means (6) for analyzing the activity state of the catalyst-forming means (3) in order to control the common fuel-feed manifold means (5) in order to regulate the quantity of fuel injected during the or each post-injection as a function of the activity state of the catalyst-forming means (3).