A review of the existing literature on the nutrition of llamas (Lama glama) and alpacas (L. pacos) revealed that these South American camelids are better adapted to the harsh environment of the Andean region than are advanced ruminants. Llamas and alpacas differ from advanced ruminants in stomach morphology, digestion, diet selectivity, and intake. Available data indicate that stocking ratios should be 1.0:1.0 for alpacas:sheep and 1.5:1.0 for llamas:sheep. Further research is recommended in digestive physiology, foraging behavior, and nutritional requirements of South American camelids. © 1989.