Abstract: This invention provides a method and apparatus for the removal of particulate matter from a fluid stream such as particulate matter from the exhaust of diesel engines. The device provides an enlarged diameter primary chamber and deflector plates adjacent an inlet end to swirl the fluid stream around the interior of the outer walls of the primary chamber. An exhaust outlet is directed to draw fluid substantially centrally from the swirling gas flow in the primary chamber such that heavier particulate matter is centrifuged away from the exhaust outlet and may be collected through a particulate matter collection means.