The SO2 solubility at various temperatures and pressures was evaluated to etermine the SO2 content in a 50 wt % H2SO4 acid solution adding new experimental solubility data for the SO2-H2SO4 binary system currently available in literature. A setup was designed and commissioned to measure the SO2 solubility at temperatures ranging from 30 degrees C to 80 degrees C and pressures up to 1000 kPa in 50 wt % H2SO4. SO2 solubility measurements in water were used to benchmark the accuracy of the setup. According to the results, the solubility of SO2 in 50 wt % H2SO4 decreased with increasing temperature despite the increase in the system pressure found at higher temperatures. The highest amount of SO2 soluble in 50 wt % H2SO4 was attained at 30 degrees C and 3.658 kPa with 13.11 g of SO2 per 100 g of H2SO4 solution. A heat of solution of -36 kJ.mol(-1) (uncertainty u(Delta H) = 5 kJ.mol(-1)) was determined.