An adjustment device (1) for adjusting the relative rotational angle position of a camshaft (2) in relation to a crankshaft of an internal combustion engine is provided, with the device having an adjustment mechanism (3), which is embodied as a triple-shaft transmission and provided with an input part (4) fixed to the crankshaft, an output part fixed to the camshaft, and an adjusting shaft (7) connected to an adjusting motor shaft (5) of an adjusting motor (6). The motor (6) is provided as an electric motor and is arranged parallel to the camshaft (2). The motor generates an adjustment torque that is transmitted to the adjustment shaft (7) via a secondary drive (18) that has a belt drive, a chain drive, a cardan drive, or an additional spur gear stage.