The increased interest and/or need to perform pediatric clinical trials to allow the marketing and safe use of a wider range of medicines in children has raised the profile of the need to conduct juvenile animal studies. It is argued that such studies may identify "unique" toxicities not seen from available adult animal and clinical data. This paper will review the current situation from an industrial, regulatory, and scientific perspective. Areas of important consideration include functional (dynamic) and kinetic differences between children and adults and specific considerations associated with testing in young animals. This paper will also review what are we currently doing? Whether we really need these studies? and What challenges lie in the future?