Radiotracer imaging studies performed on animals have the potential to play a major role in pharmaceutical development, pharmacology studies and basic biochemistry research. Recent developments in instrumentation and imaging methodology make it possible to image and quantify the kinetics of radiolabelled pharmaceuticals in a wide range of animal models from rodents to non-human primates. This article reviews the developments which have led to the current state-of-the-art, including advances in detector technologies, image reconstruction and tracer kinetic modelling. The practical issues specific to animal imaging studies are also discussed. With appropriate instrumentation and rigorous methodology, quantitative pre-clinical imaging has an important role to play in drug development.