Part of the production of the Refinery Getúlio Vargas (Paraná State, South Brazil), is transported through OLAPA Pipeline to a Marine Terminal in Paranaguá. In February/2001 occurred a displacement of a great amount of land which caused abrupt rupture of the pipeline in km 57, and 57.000 liters of diesel oil was spilled. Despite all efforts of PETROBRAS contingency team, the oil spilled reached 3 rivers (Meio River, Sagrado River and Nhun-diaquara River) and ending at the sea in Antonina Bay. Right after the incident, a monitoring program was established to evaluate short term effects. One year after the incident, long term effects were also evaluated, especially concerning benthic community and ecotoxicology on the rivers affected by the spill, and plant and birds community in region on its influence. The results point short term effects on water chemistry, but those lasted no more than one week. Short and long term effects on birds and benthic community were not detected.