This study has the aim of verifying the histological alterations in the hepatic tissue of Rana ridibunda when exposed to 0.4mg/g body weight of Actara 25WG at 4-6ºC, respectively at 22-24ºC. The toxic was administrated with intraperitoneal shots (one shot every two days, in a scheme of three weeks). A technique of light microscopy was used. At the end of the experiment. we have observed the presence of biliary pigment in the citosol. Some hepatocytes lost cellular contour. Karyomegalia and polyploidy together with accumulation of infiltrates were also observed. A large zone of fibrosis was present between hepatocytes and around blood vessels. The histological changes were more powerful at 22-24ºC.