We analysed atmospheric UV backscatter spectra obtained by the Global Ozone Monitoring Experiment (GOME) spectrometer on board the ESA European Remote Sensing Satellite (ERS-2) after the last major eruptions of Mt. Etna on Sicily (Italy) in July/August 2001 and October/November 2002. Sulfur dioxide columnar amounts were retrieved from satellite measurements and ground-based measurements. The analysis revealed that information about the plume height of volcanic eruptions and aerosol parameters is necessary for a reliable quantitative retrieval of sulfur dioxide from space-borne sensor data at periods perturbed by volcanic eruptions.