Requirement engineers face challenges in assessing the needs of elderly citizens, who typically differ a lot in terms of experiences, perspectives, and cognition. Design Thinking (DT) is a promising methodology for overcoming this barrier because it offers a structured approach for assessing users’ needs and developing new ideas. However, DT needs to be adapted to the specifics of older participants to grasp user insights fully. For instance, the endurance of older participants is limited, and collaboration with other stakeholders is hampered due to decreasing physical, cognitive, and psychological capacity. This research utilizes a design science approach for developing the SeniorDT methodology, which functions as the artifact of this study. Aim of the SeniorDT method is to facilitate older participants’ engagement. This approach is tested in practice and evaluated by observations, group discussions, and interviews. On this basis, the SeniorDT method is presented, and further opportunities and challenges for applying DT with elderly participants are illustrated. Limitations are discussed and implications for further research and practice are derived.