Artificially patinated artistic bronze was exposed to the action of 0.10 and 12.68 ppm SO2 contamination in the laboratory at 100% relative humidity. The surface layers were characterized using electrochemical, atomic absorption, X-ray powder diffraction techniques and Fourier transform-infrared spectrometry. Thermal and calorimetric studies were also performed. Some of the compounds identified were cuprite (Cu2O), digenite (Cu1.8S), yarrowite (Cu9S8), chalcocite (Cu2S), brochantite (Cu-4(OH)(6)SO4), bonattite (CuSO4 . 3H(2)O) and Sn2S3.