This paper describes the development of an expert system to provide routine consulting advice to petroleum reservoir engineers in the highly specialized field of fluid properties. Obtaining reliable reservoir fluid properties is a critical first step in various reservoir engineering studies. Knowledge of the fluid properties required for various applications and the technically appropriate and cost effective methods for obtaining the data can save time and money. The likelihood of obtaining representative data is increased. In order to provide advice on the fluid property needs for various applications and to recommend appropriate ways to obtain the requisite data, the Fluid Properties Measurement Expert System was developed. The system has been developed using an EMYCIN like expert system shell. In addition to containing over 600 rules in its knowledge base, the expert system connects to several processing programs and a database of fluid property reports. An initial prototype of an important subsystem was validated against a panel of fluid property experts. The validation methodology is also detailed.