Due to increased global business collaboration, more and more design firms are involved in international projects. This requires professionals to work together, share information and knowledge, and to adapt to each other’s work styles. There are many opportunities for misunderstanding during the processes of the design development. In the process of a design project, the design development, which includes concept design and scheme design, involves communication of concepts and comments among the designers, consultants, and the client.The objective of this research is to discuss the cultural differences among designers, focusing on work value and organizational citizenship behavior in two different countries, one Western, the other Eastern: the United States and Taiwan. The study relied on interviews and a questionnaire survey. Interior designers and architects who have experience in international projects with design firms in the United States and Taiwan were interviewed on issues regarding design development procedures, organizational structure of design firms, and the interviewees’ experience in international projects. Additionally, a closed-ended questionnaire survey was used to identify differences in work values and organizational citizenship behavior. Finally, transcripts, field notes, and data were analyzed to identify similarities and differences between the interviewees.The results of this research indicate the following differences among designers in the United States and Taiwan: (1) in attitudes toward design projects; (2) in attitudes toward teamwork; and (3) in personal interactions. The findings of this study led the researcher to make the following conclusions. First, the team structure of an international project is different than that of a domestic project because design firms have to collaborate in every phase of the project with different degrees of involvement, and coordinators and translators are needed to connect designers from different countries. Second, the process of an international design project is more complicated than that of a domestic project because each design firm involved in the international project has different responsibilities and has to integrate with the other firm. Third, designers in different countries have different values and attitudes influenced by their culture, which impact an international team, especially when the teams have to work together, face-to-face. Finally, this study provides some suggestions and reminders to designers who intend to participate in international projects.