Previous studies have demonstrated that pharmacological hypothermia could protect the brain from ischemia or traumatic brain injury in rodent models. However, it remains unknown how the brain is affected by the hypothermia in patients as the physiology and brain metabolism of human are very different from rodents. Large animal models have been recommended to improve clinical translation in the study of ischemia . In the present study, the effects of drug-induced hypothermia on the brain of adult macaque monkeys were examined using diffusion MRI. The results suggested large animals play an important role in neuroprotection research of stroke.