During the second half of the first millennium BC, thousands of hollow cast bronzes were produced in Egypt. Among them are animal figures that were used as votive offerings to the deities to whom the animals represented were sacred. The author discusses the examination of a variety of hollow cast ibis and cat bronzes in the Metropolitan Museum of Art and several other institutions. The function of these bronzes in ancient Egypt and general observations about their manufacture and decoration are presented. Conventional x-radiography proved to be the most useful tool in assessing technical features such as core supports, the quality of the castings, the shape of the internal cavities, the presence of core or mummies in the bronzes, locations and methods of joins, etc., that are useful in the characterization of ancient Egyptian hollow cast bronzes of this period. Alloy composition and surface condition are also considered.