Abstract: A chimney fire extinguisher includes a bracket assembly by which a container of fire-extinguishing fluid is mounted outside the chimney. One leg of a U-shaped member included in the bracket assembly abuts the inner wall of the chimney, while a bracket plate adjustably attached to the web portion abuts the outer wall of the chimney. By adjusting the spacing between the bracket plate and the U-shaped member, it is possible for the assembly to accommodate chimneys of different thicknesses.