A massage device has a massage head distance adjustment mechanism. In one embodiment, the massage head distance adjustment mechanism includes a first motor, a first worm coaxially connected to the first motor, a first worm wheel meshing with the first worm, a first gear meshing with the first worm wheel, and a pair of second gears having one second gear meshed with the first gear. The pair of second gears meshes with each other. In operation, the first motor drives, in sequence, the first worm, the first worm wheel, the first gear, and the pair of second gears, thereby causing the pair of massage heads to move along a corresponding pair of arc-shaped slots. Accordingly, the distance between the two massage heads is adjusted.