Most medications, intended for children are used without performing clinical tests, which means that the manufacturers, as well as doctors, when prescribing the children’s doses according to the child’s age and weight, do not have the necessary efficiency and safety data and do not know the probability of adversary effect of the treatment. The ways of prescribing the medication and the forms of use of medication by children must be based scientifically otherwise there is a probability of treatment by an insufficient dose or even an overdose situation. The aim of the article is to provide an overview of the historical prerequisites of the situation, pertaining to treatment of children with medication and to summarize the legal regulation of pediatric clinical tests of medicinal preparations, in order to ensure that children are treated by safe and efficient medications in the United States of America and in the European Union. The article also provides the overview of the legal acts of the Republic of Lithuania, regulating the performance of pediatric clinical tests
