Abstract: A mold is provided for use in forming a chimney crown on the top of a chimney shell. The mold includes four side sections and four corner sections which are assembled together to form a complete unit. Each side section and each corner section has a base for contacting a top surface of the chimney shell and a band extending downwardly from the base for contacting an outer side surface of the chimney shell. Since part of this base extends outwardly beyond the chimney shell, the chimney crown overhangs the chimney shell preferably in a cantilever manner. Each side section of the mold also has an upper leg and a lower leg extending from the base at the outer end thereof. A hook trough extends inwardly from the upper leg into the chimney crown for anchoring the mold and for carrying water to drainage holes in the corner sections of the mold. A rope may be disposed in the hook trough to act as a wick for drawing excess moisture from the chimney crown.