A valve actuation system for an internal combustion engine The valve actuation system (S) for an internal combustion engine comprises: ·a rocker (6) pivotably mounted around a pivot axis (A6), comprising: ·a driven end portion (62) for cooperating with a rotating cam including a main bump and at least one smaller auxiliary bump; ·an actuating end portion (63) including a piston (8) for opening at least one valve of the engine following the cooperation of the driven end portion (62) with a bump of the cam, the piston (8) being slidably mounted relative to the rocker (6) between a extended position allowing said piston (8) to open said valve when the driven end portion (62) contacts the auxiliary bump, and a retracted position preventing said piston (8) to open said valve when the driven end portion (62) contacts the auxiliary bump; ·a fluid circuit for causing the piston (8) to move from its retracted position to its extended position; ·a reset circuit comprising a reset valve (99) rotatably mounted relative to the rocker (6), between an inactive position, and an active position in which the reset valve (99) causes the fluid to be drained out of the fluid circuit to allow the piston (8) to move towards its retracted position; ·a lever (7) pivotably mounted around a pivot axis (A6), the lever (7) having a driven end portion (72) adapted to cooperate with a rotating reset cam including a bump, and an actuating end portion (73) for rotating the reset valve (99) from its inactive position towards its active position following the cooperation of the lever driven end portion (72) with the bump of the reset cam; ·rotational coupling means (75, 95) between the lever (7) and the reset valve (99), said rotational coupling means having a transmission ratio greater than 1.