The aim of the study was to test the prediction performance of the fatty acid (FA) composition of beef (Rectusabdominis, RA) with a NIRS (near infrared spectroscopy) equipment. In order to have a representative database ofFrench beef FA composition, 364 RA were sampled on carcasses from different rearing systems (dairy or beef ; youngbulls, cows, steers or heifers ; pasture, hay or corn silage with or without extruded linseed concentrates). FAcomposition was assessed using gas chromatography and spectra were measured at wavelengths between 400 and2500nm. The results show that NIRS accurately predicts several individual FA (16:0, 18:1d9cis) and FA groups (totalsaturated, monounsaturated FA) (RPD>2.0). For other FA and especially polyunsaturated fatty acids (PUFA) n-6 or n-3, the performances should still be improved for quantitative purposes