Cassava (Manihot esculenta) is the only commercial species of the genus, cultivated mainly for its starchy tuber roots. Cassava seeds are known to be rich in oils and fats. However, there are very scant reports on the content and properties of oil from cassava seeds and its wild relatives, which usually produce higher amount of seeds with large diversity in shape and size. Seeds of 106 accessions (12 species of Manihot) from the collection of Embrapa were evaluated for oil content (NMR) and fatty acids by gas chromatography. The oil content ranged from 17.2% (M. caerulescens) to 30.7% (M. flabellifolia) with 4 clusters of species with significant differences. Five fatty acids were found in all species with the following general profile: linoleic (C18:2) 61.7%; oleic (C18:1) 19.7%; palmitic (C16:0) 12.4%; stearic (C18:0) 4.5%; and linolenic (C18:3) 1.6%. The concentration of all fatty acids varied significantly within species and between accessions of Manihot species. The highest content of linoleic acid was in seeds of M. peruviana, M. pseudoglaziovii, M. cecropiaefolia, M. flabellifolia, M. glaziovii, and Manihot spp. (average of 65%); and the highest oleic acid was in M. caerulescens, M. esculenta, M. anomala, M. dichotoma, and M. tomentosa (average of 23%). The collection of Embrapa’s Manihot germplasm present a large variability of fatty acid composition, probably influenced by the great diversity of wild species and accessions, the year the seeds were harvested and seed size. The Manihot wild collection is a valuable source for cassava breeding programs.