This interspinous implant is able to be engaged between the spinal processes of two vertebrae and formed by a block of elastically deformable material. According to the invention, the block is subdivided into a central part made from a first elastically deformable material and two lateral parts made from a second elastically deformable material, more rigid than the first material. The lateral parts are situated on the two opposite lateral sides of the central part, that is to say on the sides intended to be situated longitudinally on each side of the spinal processes after implantation, and being connected to the central part.
