Preclinical or nonclinical evaluation is an integral part of the development of any drug. The process of developing a new radiopharmaceutical includes rigorous testing before it can be cleared for use in humans. There must be in-depth characterization of its behaviour to assess its safety and suitability for the intended clinical application. This publication provides a baseline guide for preclinical evaluation of radiopharmaceuticals that will give its readers a general review of the requirements of a facility and insight into the various scientific activities that constitute this process. The principles and protocols discussed herein will provide guidelines for biological assessment of candidate compounds, which are consistent with the principles of good laboratory practices to generate valid nonclinical scientific data towards approval for clinical translation. This publication is intended not only for researchers engaged in radiopharmaceutical development, but also for the Member States planning to set up or upgrade facilities for radiopharmaceuticals' research.