In view of the client distrust in engineer, in the current context in Taiwan, it is uncommon to employ private engineers for public construction projects. In this study, which analyzed data of the period between 2003 and 2006, a questionnaire was administered to collate the viewpoints of clients, contractors, and architects/engineers (A/Es) involved in public construction projects that employed engineer. The opinions of participants regarding trust factors that influenced client evaluations of engineer were analyzed. Twenty-six trust factors were analyzed via interviews and a literature review. These factors were grouped using the principal component method and the varimax rotation approach. Analytical results indicate that the primary factors affecting the trust in engineer employed in public construction projects in Taiwan may be classified into three categories and eight factors. Variation among three trust relationships-calculative, relational, and institutional-with regard to trust in the handling of projects was assessed. Analytical results demonstrated the validity of the trust model proposed by Rousseau . The influence of institutional trust exists throughout the length of a project, with any variation being minor. Interactive influences exist between calculative trust and relational trust. These types of trusts fluctuate as a project progresses. The results of this study serve as a reference for managing decision making with regard to ensuring client trust in engineer.