An outdoor unit for an air conditioner may include a case, a controller disposed in the case, a coupling member configured to connect the case to the controller, and a cooling pipe coupled to one side of the controller so as to perform heat-exchange with the controller. The controller may include a first controller connected to the coupling member so as to be rotatably coupled to the case, and a second controller coupled to the cooling pipe so as to be fixedly installed inside of the case.