The fetotoxic effect of 2,4-dichlorophenoxyacetic acid (2,4-D) was investigated. Histological and histochemical changes in the liver of newborn, jung and adult rats exposed to the herbicide from the prenatal period to the end of an experiment were evaluated. The experiment used 90 male and female, Wistar, aged to 10 weeks rats, divided into two groups: I-control-30 and II-60 animals which received the water solution of 2,4-D acid sodium salt in a daily dose of 250 mg/kg b.w. It was given with drinking water every day. The animals were sacrificed after 24 hours, 4, 6, and 10 weeks of the experiment. The results obtained showed that the administration of 2,4-D acid to rats in the prenatal and postnatal period, in a dose inducing subacute intoxication leads to histological and histochemical changes in the liver. The observed changes indicate disorders in energetic processes in hepatocytes and are morphological exponents of detoxicative processes there. They are most intensified with newborn rats. It suggest also, the pregnants ought not to work with 2,4-D and should avoid any contact with herbicides belongs to the 2,4-dichlorophenoxyacetic acid group.