An adjusting device for positioning shower head includes a holder movably connected to a rod and a clip for positioning a shower head is rotatably connected to the holder. A frame is connected to the holder and a clamp is movably located between the holder and the frame. The clamp has a clamp shoe which is in a first position to contact the rod or in a second position to be removed from the rod. The clamp has an insertion extending therefrom which extends through the frame and is connected with a lever unit. A spring is mounted on the insertion. The lever unit can pull the insertion to remove the clamp shoe away from the rod to allow the holder to be moved along the rod.