Abstract: A duct cleaning device, including a flexible conduit with a first, inlet end and a second, outlet end. An end cap with a central hole is attached to the first end; a connector adapted for coupling the device to a vacuum hose (or the inlet of a vacuum cleaner) is attached to the second end. A flexible, radially-projecting brush is attached to the exterior of the conduit, extending helically about the conduit; a plurality of throughholes (some of which carry flexible, radially-projecting tubes) are positioned near the brush. In operation, the device is connected to a source of vacuum. The first end is rotated while being moved into (or removed from) a duct, while the brush sweeps the interior surface of the duct to dislodge particulates of house dust and other contaminants from the surface. The particulates are swept into the conduit through the hole in the end cap and the throughholes in the conduit.