An enterprise that uses web services for the conduct of business can benefit from computer-based monitoring for its normal course of business. Services that are unavailable, delayed, inadequate, and/or provide poor or delayed information flow, all hinder or prevent the normal course of business. In extreme cases they may prevent business from being conducted. The proper performance of the service-oriented approach, the communication flow and the services themselves directly equate to the health and vitality of the enterprise. By health we mean, availability, performance, integrity, and reliability of web services. This paper reviews an agent based approach for web service monitoring in an enterprise environment. The agents create and collect information about the services. The paper also provides a definition of events that need to be monitored and the elements that should be recorded. Some information about critical events is time critical and should be sent as alerts to monitoring personnel for review and possible action. These processes are currently being implemented in a major defense enterprise.