Current research integrity (RI) guideline development methods can miss diverging perspectives, but these are crucial for accounting for stakeholders’ needs across countries and disciplines. Co-creation could be a promising RI guideline development method. We conducted interviews with 22 stakeholders taking part in an RI guideline co-creation project. Our results indicate that stakeholders believe that co-creation stimulates the expression of diverse perspectives. Furthermore, they say that co-creation is powerful in engaging stakeholders, and increasing support for the guidelines. Our interviewees expressed that various features of co-creation contribute towards evoking a broad range of valuable ideas. Co-creation was deemed valuable for producing a rich harvest, including reaching agreement on crucial guideline elements, and for understanding important nuances. Our interviewees supported the use of a multi-stage co-creation methodology for the initial phases of RI guideline development. Based on these findings, we recommend guideline developers to consider using co-creation to bring together diverse perspectives.