This paper presents the design of a real-time web centric intelligent health care diagnosis system using unified modeling language (UML) to support diabetes diagnosis. Using this expressive language we are addressing all the views needed to develop real time web centric intelligent health care diagnostic system. UML which is a standard language for software blueprints and whose vocabulary and rules focus on the conceptual and physical representation of the system is used to represent a web based diabetes expert system. As a case study, the web based diabetes expert system WEBDIACIN is presented. Diabetes is the single most important metabolic disease, which can affect nearly every organ in the body. It has been projected that 300 million individuals would be afflicted with diabetes by the year 2025. In India, it is estimated 19.4 million individuals are victims of this deficiency. We propose a medical network based on state-of-the-art medical kiosk that addresses the problems of providing preventive and diagnostic health care. The combination of an expert system with the benefits of web technology allows that several doctors and patients use the benefits of the system of support the detection of diabetes. The rules of the expert system are applied to diabetes, and the related diseases in the diabetes evaluation.