Support device is adjustable by an electric motor, for supporting cushioning of a piece of furniture for sitting and/or lying on, and has a base body with a first support part that is adjustable, in particular pivotable, with respect to a second support part. Support device has an electric motor adjusting device connected with first support part for adjusting it. Adjusting device has a first and a second adjusting unit second adjusting unit which are provided on opposite longitudinal sides of base body. A rotationally supported component of the first adjusting unit is connected in rotationally fixed manner to a similar component of the second adjusting unit via a connecting shaft, and a shared electric motor is associated with the adjusting units. The rotationally supported component in each case is an input-side transmission element of a reduction gear.
