User satisfaction has been found to be an adequate proxy for contribution of Information Systems (IS) to organizational performance (Gelderman, 1998). However, although IS projects plan and estimate cost and schedule, quality, the third leg of the iron triangle, defined as the degree to which a system, component, or process meets specified requirements and customer/user needs and expectations (The IEEE Standard 610.12-1990) is seldom estimated. Assessing user satisfaction after the IS product is developed has limited value. Often the situation at this stage is non-remediable resulting in wasted efforts and loss of scarce resources. This paper investigates the feasibility of estimating user satisfaction even before the IS development has commenced. The method developed in the study was tested empirically and can be used in practice to estimate user satisfaction for a given requirement set and to obtain changes in estimates if requirement sub-sets are either included or excluded from it.