In recent years, the use of metasynthesis as a research method has increased within nursing science. In the present paper, we focus on examining the phases of metasynthesis, using a study of patients' duties as an example. The aim of this paper is to increase the understanding of synthesis as a method in order to promote research trustworthiness by making the research process more transparent and thereby increasing the readers' awareness of it. We formulated a purpose for each phase of metasynthesis in order to better understand synthesis as a rational thinking process. We found that the collaboration of several researchers during all phases of metasynthesis is needed in order to maintain research ethics and trustworthiness. In addition, further study of the phases of metasynthesis is needed for improving research methods in order to produce new, accumulated knowledge based on previous qualitative study.