Informations on postfire ecological effects in southern Switzerland are still scarce. Studies about postfire soil erosion have even not yet been carried out. To close this gap of knowledge we installed bounded runoff test plots (30 m²) on three recently burned test sites with different fire frequencies (high, medium and low). First results show that runoff from burned areas can be up to more than two times higher than runoff from unburned areas. Double ring infiltrometer experiments further showed that the rate of infiltration of water under burned conditions is much lower than under unburned conditions. Soil loss reached up to 150 kg/30 m² in the first two years after a forest fire on the test site with low fire frequency. Due to the low bulk density of 0.5 g/cm³ of the soil this corresponds at this test site to a maximum loss of more than 9 mm soil colum in two years. On the other hand, there was no soil erosion on the test site with high fire frequency, even though the slope is almost as steep (60% - 70%) as the former and the rainfall erosivity comparable. The maximum postfire soil loss on the test site with medium fire frequency ranged up to 10 kg/30 m². These results suggest that forest fires seem to have a strong influence on postfire runoff, water infiltration and soil erosion in southern Switzerland.