An adjustable wrench with strength enhancing structural design includes a body including a grip end and a driving head. The driving head includes a fixed jaw and a movable jaw. The movable jaw engages and is operably movable in a groove. The groove includes two lateral walls facing oppositely and spacing from each other. Each of the two lateral walls includes a first surface and a second surface. The first surfaces of the two lateral walls face oppositely and are separated by a space. The first and second surfaces of each of the two lateral walls have a common edge and an included angle less than 90 degrees. The movable jaw includes two slopped surfaces corresponding to and abutting against the second surfaces of the two lateral walls.