The oil content and fatty acid profiles of Euphorbiaceae from Caatinga, totaling 100 specimens, 33 species and 26 localities were determined. Intraspecific variation of fatty acid profiles were observed in some species. Many samples are potential sources of seed oil with a variety of potential industrial uses. Large seeds with high oil yields characterize species of Cnidoscolus, Croton, Jatropha and Manihot. Most samples contain linoleic acid as main seed oil constituent. Oils with oxidation stability due to high contents of palmitic and oleic acids were obtained from samples of Sebastiania. Samples of Chamaesyce and Euphorbia stand out by high contents of linolenic acid. Some samples of Croton contain substantial contents of azelaic acid. (C) 2014 Elsevier Ltd. All rights reserved.