Abstract: A stackable chimney cap includes a stackable cage/base unit composed of four parts, each part being formed by bending from a blank of metal sheet and the four parts being permanently joined together by weldments. Trapezoidal-shaped, perforated side walls of the four parts together form a pyramidal cage portion of the cage/base unit having a rectangular opening at a planar base edge thereof. Bent flange portions on each part together form a peripheral mounting base portion of the chimney cap that extends outwardly from the base edge of the cage portion with respect to the base opening. A stackable hood separate from the cage/base unit is attached to the upper edge of the cage portion at the point of sale or use of the chimney cap. Several chimney caps, with the cage/base units and hoods stacked separately, can be boxed together for storage, shipment and retail stocking, using a fraction of the space required for the same number of fully assembled chimney caps of the same size.