Jicaro (Crescentia alata) is a tropical tree native to Mesoamerica well adapted to severe drought conditions. The seeds of the fruits were analyzed for protein, fatty acid, dietary fiber, phytate, polyphenol, tannin, tocopherol, sugar, mineral, amino acid and trypsin inhibitor contents. The jicaro cotyledons contained 43.6 ± 1.15 g protein/100 g and 38.0 ± 0.20 g fat/100 g (d.w.), which is comparable to most protein-rich and oleaginous seeds. Among the lipids, 77.6% were unsaturated fatty acids, particularly oleic acid, and essential amino acids represented 16.0 ± 0.9% (d.w.) of the protein fraction, which is similar to soybean amino acid contents. A proteomic analysis and SDS-PAGE electrophoresis revealed that the proteins are mostly of low molecular weight (~10 kDa), and the storage protein 2S albumin dominated. Jicaro seed trypsin inhibitory activity was low (0.1 trypsin inhibitor units TIU/mg), which enhances the digestibility of its proteins. The jicaro seed cotyledon represents an autochthonous and high-quality food source.