An anatomico-topographical study of the putamen was performed on the cerebral hemisphere of 25 adults. The mean diameters of the putamen were: 44 rom anterioposterior, 41 vertical and 8.5 rom horizontal. A 30x20 rom cortical area in the insula middle third was projected precisely on the external surface of the putamen. We consider that the transinsular approach to the putamen provides more advantages than the transfrontal approach.