This study presents the results of an examination of the mummified brain of a pleistocene Woolly mammoth (Mammuthus primigenius) recovered from the Yakutian permafrost in Siberia, Russia. This unique specimen (39 440 – 38 850 years BP) provides the rare opportunity to compare the brain morphology of this extinct species with a related extant species, the African elephant (Loxodonta africana). An anatomical description of the preserved brain of the Woolly mammoth is provided, along with a series of quantitative analyses of various brain structures. These descriptions are based on visual inspection of the actual specimen as well as the qualitative and quantitative comparison of CT imaging data obtained for the Woolly mammoth in comparison to MR imaging data from three African elephant brains. In general, the brain of the Woolly mammoth specimen examined, estimated to weigh between 4230 – 4340 g, showed the typical shape, size and gross structures observed in extant elephants. The quantitative comparative analyses of various features of the brain, such as the amygdala, corpus callosum, cerebellum and gyrnecephalic index, all indicate that the brain of the Woolly mammoth specimen examined has many similarities with that of modern African elephants. The analysis provided herein indicates that a specific brain type representative of the Elephantidae is likely to be a feature of this mammalian family. In addition, the extensive similarities between the Woolly mammoth brain with the African elephant brain indicates that the specializations observed in the extant elephant brain are likely to have been present in the Woolly mammoth.