A surface treating appliance, such as a vacuum cleaner, includes a main body, a surface treating head and a support assembly. The support assembly is rollably mounted to the main body for allowing the main body to be rolled along a surface. The support assembly also houses a component of the appliance, such as a motor for driving a surface-agitating device. Alternatively, or additionally, the support assembly may accommodate a fluid inlet for receiving fluid flow, a fluid outlet for exhausting fluid and a device for acting on the fluid flow received by the inlet such as a filter or suction apparatus.