Abstract The two genera comprising the subtribe Blaesiina (Scarabaeidae: Cetoniinae: Gymnetini) are reviewed. Each genus contains two species, with Blaesia Burmeister occurring in southern South America and Halffterinetis Moron & Nogueira occurring in northern Mexico. Descriptions, keys, distributions, biology, and illustrations are provided. The biogeography of the Blaesiina is discussed with a hypothesis to explain the current disjunct distributions. I provide a new state record for Halffterinetis gonzaloi Moron & Nogueira in San Luis Potosi, Mexico.