33 species were compared for 12 disease categories over 3 years of laboratory housing. There were low correlations between popularity, birth, death, and illness rates. Highest rates were: birth, Macaca nemestrina; illness, Pongo pygmaeus; death, Cercopithecus aethiops. Lowest rates were: birth, Lemur catta; illness, Sanguinus mystax; death, Galago crassicaudatus. Galago crassicaudatus and Macaca fasicularus had low disease and high birth rates. © 1979, Royal Society of Medicine Press. All rights reserved.