Recovery animals are used in pharmaceutical development to provide information on the potential for a toxic effect observed in animals to translate into long term human risk. They are included on toxicology studies to assess whether effects observed during dosing persist or reverse once treatment ends. The group devised a questionnaire to collect information on the use of recovery animals in general regulatory toxicology studies to support first-in-human clinical studies. Questions focused on study design (e.g. species, recovery duration and the number of animals used), the rationale behind inclusion or exclusion and the impact this had on internal and regulatory decisions. Data on 137 compounds (53 biologicals and 78 small molecules) from 259 studies was provided by 22 companies and showed that there was wide variation inwhere,when andwhy recovery animalswere included. An analysis of individual study and programme design shows that there are opportunities to reduce the use of recovery animals in certain circumstances which would not impact drug development.