In recent years an increase in the occurrence of debris flows has been observed in various regions of Brazil. These mass movements can be characterized by the expressive volume of material mobilized during a relative short period of time, long distances of travelling, high velocity and high transport capacity. On January 13, 2014 an extreme precipitation event produced landslides, debris flows and flash floods in two basins. The study area is located in the “Guarda-Mão” watershed, at Itaoca municipality, which is about 348 km southern of São Paulo city. The basin is lithologically very homogeneous, because the bedrock consists of granitic rocks. The debris flow and flash floods occurred during convective summer storms, with rain intensities of 210 mm in two hours. The damage caused by the occurrence of debris flow included destruction of plantations, houses, bridges, roads, two missing people and 25 deaths.