The tamarind seed, sweet variety, is a promising source of naturalantioxidants. In this work the best yield and antioxidant activity were obtained with 100% of pressurized ethanol at 250 bar and 50 C in comparison with those obtained by Sohxlet. The mathematical model of Martínez et al. (2003),was the one that best fitted the experimental data of the extracts obtained by sub and supercritical CO2 with a MSE of 1.7245 105. It is an important tool for process optimization and scale-up. Also, fatty acids compounds with potential antioxidant activity were found in the extracts such as linoleic and oleic acid, as well as others like cis-10- heptadecenoic acid and n-hexadecanoic acid (palmitic acid).