Abstract: A tennis serve practice device includes a frame means having four interconnected frame members which define a trapezium-shaped quadrilateral opening. The size and configuration of the opening is adjustable in calculated accordance with the effective serving height of the user so that the device precisely simulates serving conditions on a regulation tennis court. If the ball served by the user passes through the opening, it would have landed fairly in the service court on a regulation tennis court. A net means loosely disposed behind the opening forms a pocket which receives and retains the balls which pass through the opening. By moving or removing one of the frame members, the device is convertible to a low net for tennis or paddle tennis games or to a high net for volleyball, shuttlecock or other games requiring a net type structure.