The invention concerns an electromechanical drive for a door or the like, with a motor and a transmission, which are connected with each other, wherein a drive gear in the form of a gear wheel or the like is present on a drive shaft of the transmission and cooperates with means for moving the door or the like, preferably in or on a guide rail. The drive has a modular design, and it has a compact power unit that can be used with different types of mounting units for different doors. In this regard, the power unit is equipped with a standard mounting bracket. In addition, different housings can be used for different areas of application.