The result of the use of drugs in the newborn may be strongly influenced by the peculiar state of the neonate, characterized by the immaturity, at birth, of the processes controlling the absorption, distribution, metabolism and excretion of drugs. Additional important factors that may affect drugs' bioavailability and toxicity are gestational age, birth weight, intrauterine growth restriction, gender and, especially, liver function immaturity. Because of the high susceptibility to infections, antibiotics, in particular ampicillin and gentamicin, are the most widely used drugs in newborns. Erythromycin is often used for the therapy of gastrointestinal dismotility, while azithromycin has been proposed for the prevention of bronchopulmonary dysplasia. Prostaglandin synthesis inhibitors, like indomethacin, are administered on the first days of life to close the patent ductus arteriosus. All these drugs have been proved to can give rise to hepatotoxicity. The acute and chronic liver toxicity due to the most widely used drugs in the neonates will be here reviewed.