Anthocyanin pigment was extracted from hulls of a sunflower genotype, Neagra de Cluj, using aqueous SO2 solutions of varying concentrations. Thermal stability of the pigment was studied between 65–95°C, and pH 1.0–5.0. Thermal degradation of the pigment followed first order kinetics. Calculated activation energy was 23.1 ± 2.2 kcal/ mole. Extraction of hulls with 1000 ppm SO2 solution gave highest anthocyanin content and best thermal stability. The pigment was most stable at pH 3.0.