Methylxanthines are alkaloids found in natural products such as tea, coffee and guarana. These alkaloids are commonly used in cola drinks and pharmaceutical products due principally to their stimulant and diuretic effects on the human organism. In this work, experimental data on the supercritical CO2 extraction of caffeine, theophylline and theobromine from herbal mate tea, a beverage traditionally consumed by the gauchos of southern Brazil, the Argentine, Paraguay and Uruguay, were obtained using high pressure extraction Equipment that allows adequate control of temperature and pressure. The continuous extraction/fractionation of mate tea leaves, Ilex paraguariensis in nature using carbon dioxide was carried out at 313.2 and 343.2 K and pressures of 13.8 and 25.5 MPa. Extraction/fractionation curves revealed the large influence of temperature and pressure on extraction yield. CO2 was also found to show a higher selectivity for caffeine than for theophylline and theobromine.173251259