System for deactivating at least one determined cylinder (1, 2, 3, 4) of an operational multicylinder engine, wherein each cylinder (1, 2, 3, 4) of said multicylinder engine comprises an intake duct with an inlet connected to the intake manifold and an outlet connected to the cylinder (1, 2, 3, 4) in order to allow the intake of the combustion gases from the intake manifold towards the cylinder (1, 2, 3, 4), the system comprising: - a first movable shut-off means (8, 20) designed to shut off the inlet of said intake duct of the determined cylinder (1, 2, 3, 4), the first shut-off means (8, 20) being movable between a first position for allowing the intake of the combustion gases towards said intake duct and a second position for shutting off the intake of the combustion gases towards said intake duct, - a recirculation duct designed to connect said intake duct of said determined cylinder (1, 2, 3, 4) to a supply for exhaust gases, - a second movable shut-off means (10, 30) designed to shut off said recirculation duct, the second shut-off means (10, 30) being movable between a first position for shutting off the communication between said recirculation duct and the supply for exhaust gases, and a second position for allowing this communication, characterized in that the first movable shut-off means (8, 20) and the second movable shut-off means (10, 30) are connected in order to move simultaneously, the first movable shut-off means (8, 20) being connected to a rotation shaft provided with a gear system and the second movable shut-off means (10, 30) being provided with a rack, said rack being in contact with said gear system to allow the first movable shut-off means (8, 20) to move between its first position and its second position by rotation, and to allow the second movable shut-off means (10, 30) to move simultaneously by translation between its first and its second position. - a first movable shut-off means (8, 20) designed to shut off the inlet of said intake duct of the determined cylinder (1, 2, 3, 4), the first shut-off means (8, 20) being movable between a first position for allowing the intake of the combustion gases towards said intake duct and a second position for shutting off the intake of the combustion gases towards said intake duct, - a recirculation duct designed to connect said intake duct of said determined cylinder (1, 2, 3, 4) to a supply for exhaust gases, - a second movable shut-off means (10, 30) designed to shut off said recirculation duct, the second shut-off means (10, 30) being movable between a first position for shutting off the communication between said recirculation duct and the supply for exhaust gases, and a second position for allowing this communication, characterized in that the first movable shut-off means (8, 20) and the second movable shut-off means (10, 30) are connected in order to move simultaneously, the first movable shut-off means (8, 20) being connected to a rotation shaft provided with a gear system and the second movable shut-off means (10, 30) being provided with a rack, said rack being in contact with said gear system to allow the first movable shut-off means (8, 20) to move between its first position and its second position by rotation, and to allow the second movable shut-off means (10, 30) to move simultaneously by translation between its first and its second position.