The increasing development and use of expert systems raises questions concerning the liabilities of those involved in their development and use. These liabilities were analyzed according to the laws of the United Slates, with respect to various types of expert systems including medical systems. No court decisions have been made concerning expert system liability-Cases that may be applicable to expert system liability cases were therefore analyzed to provide insight into possible future court decisions concerning expert systems. The major factor in determining these liabilities is the classification of software. Software can be classified as a product or a service. If classified as a product, strict product liability will be imposed. If classified as a service, professional misconduct will be imposed. This determination of the software classification will most likely be made on a case-by-case basis, because in each case the expert system will be functioning in a different environment with a different value placed on the advice given by the expert system.