n this paper we present a method to perform run-time monitoring of distributed applications built on top of a distributed object oriented processing environment. For this, we instrument the code at the compilation time in order to send notifications to an Observer when relevant events occur in the system, the instrumentation is done in an automated manner, requiring a minimum of programmer interactions. One advantage of our run-time monitoring approach is that it does not hinder the development process already adopted. In our proposal, the choice of the information to select for observation is made simple by the definition of events which are generic and useful for all distributed applications, the user does not need to specify them. We apply our run-time monitoring method to a telecommunication services implemented on top of the distributed processing environment CORBA Orbix from IONA.