Trust is widely recognized as an essential factor for the continual development of business-to-customer (B2C) electronic commerce (EC). Many trust models have been developed, however, most are subjective and do not take into account the vagueness and ambiguity of EC trust and the customers’ intuitions and experience when conducting online transactions. In this chapter, we describe the development and implementation of a model using fuzzy reasoning to evaluate EC trust. This trust model is based on the information customers expect to find on an EC Web site and that is shown from many studies to increase customers trust towards online merchants. We argue that fuzzy logic is suitable for trust evaluation as it takes into account the uncertainties within EC data and like human relationships; it is often expressed by linguistic terms rather then numerical values. The evaluation of the proposed model is illustrated using four case studies and a comparison with two other models is conducted to emphasise the benefits of using fuzzy decision system.