Abstract: This case study describes research into interventions to enhance stroke patients’ ability to communicate. Because patients’ cognitive abilities are compromised, it is argued that they may lack the capacity to consent and that surrogate consent should be required. In South Africa, this would make conducting the research difficult because only court-appointed curators are “legally appropriate” substitutes for research enrolment. Here, the research ethics committee must balance legal requirements and ethical concerns. It must also balance protection and respect for autonomy, even for cognitively compromised participants. First, incapacity should not simply be assumed but should be individually assessed. However, stroke patients present a further complication for capacity assessment because they may retain the capacity to reason but have lost the ability to communicate effectively. Second, the research ethics committee must decide whether recruitment should be restricted or whether incapacitated participants may be enrolled. Given the low risk of harm, incapacitated persons could be enrolled by proxies.