These sessions are full of interesting topics related to the development and present status of pharmacokinetics. This conference will deal with the problems and perspectives in the joint field of pharmacology and pharmacokinetics. We are grateful to the Fogarty International Center for organizing this conference and for having invited such distinguished scientists to review the subject and to take part in the discussion. Since its first appearance as a “Grenzgebiet” in Professor Thorell’s well-known paper, pharmacokinetics has developed in its theoretical aspects as well as in its practical applications. Its impact in the practical field can be judged by the fact that the European Economic Community requires a careful pharmacokinetic study for every drug put on the market, in particular for antibiotics, chemotherapeutic agents, and contrast media. Even with this interest of the drug companies, one aspect of pharmacokinetics, namely its application to dosage regimen, has not yet been explored as it deserves.