Red grape pomace (RGP), an abundant wine industry solid waste, was used for the recovery of polyphenols and anthocyanin pigments, using ultrasound-assisted extraction and water/glycerol mixtures as the solvent. Glycerol concentration (C-gl) and liquid-to-solid ratio (R-L/S) were first optimized by implementing Box-Behnken experimental design and the process was further studied through kinetics. The optimal conditions were found to be C-gl = 90% (w/v) and R-L/S = 90 mL g(-1), and under these conditions the extraction of total polyphenols (TP) and total pigments (TPm) obeyed first-order kinetics. Maximum diffusivity (D-e) values were 4.22 x 10(-12) and 12.59 x 10(-12) m(2) s(-1), for TP and TPm, respectively, and the corresponding activation energies were (E-a) 13.94 and 8.22 kJ mol(-1).