Abstract: An aftertreatment system for use in a lean burn engine is disclosed. In one embodiment, the aftertreatment system includes a first catalyst in communication with an exhaust stream from the engine; a selective catalytic reduction catalyst in communication with the exhaust stream and positioned downstream of the first catalyst; and a lean NOx trap in communication with the exhaust stream and positioned downstream of the selective catalytic reduction catalyst; with the proviso that the first catalyst is not a selective catalytic reduction catalyst. A method for treating lean burn engine exhaust gases using the aftertreatment system is also disclosed.