An implantable spinous process fixation device includes an elongated component, top and bottom pivoting wing components, arranged opposite and parallel to the elongated component and separated from it by a spacer. First and second spinous processes of first and second adjacent vertebras are clamped between a top portion of the elongated component and the top pivoting wing and between a bottom portion of the elongated component and the bottom pivoting wing, respectively, by pivoting the top and bottom pivoting wings toward the top and bottom portions of the elongated component. The clamping of the spinous processes stabilizes the positions of the adjacent vertebras and prevents them from moving relative to each other.