In the present work we investigated the glyceride and sterol compositions of Astrocaryum macrocalyx ("huicungo") kernel fat. This species is native from the Peruvian Amazonia (Iquitos). Gas chromatographic analysis of the fatty acids revealed 8 components, among which lauric (54.5%) and myristic (21.9%) acids predominate. The sterol profile is classic; β-sitosterol and campesterol are the main constituents (74.3 and 12.0% respectively) while the A-sterols were detected in minute amounts. X-ray diffraction measurements showed that Astrocaryum macrocalyx kernel fat is stabilized in the β-j-2 polymorphic form at ambiant temperature.