Background: The assessment and management of a person with aphasia for whom decision-making capacity is queried represents a highly complex clinical issue. In addition, there are few published guidelines and even fewer published accounts of empirical research to assist. Aims: The research presented in this paper aimed to identify the main issues for speech pathologists when decision-making capacity for legal and related matters arose for their clients with aphasia, and to describe qualitatively the nature of these issues and the practices of the speech pathologists in these situations. Methods: & Procedures: The methodology was informed by the qualitative research paradigm and made use of the semi-structured interview methods developed for the Critical Incident Technique. Nine speech pathologists, with a range of clinical experience between three and 27 years, were interviewed by telephone, with verbatim notes being taken on-line by the interviewer. The speech pathologists described a total of 21 clients (15 male, six female) with acquired neurological communication disorders (including cerebral vascular accident, traumatic brain injury, and tumour) whose care had raised critical incidents for the speech pathologist in relation to legal and related matters. These verbatim notes were qualitatively analysed using "NVivo" qualitative analysis software. Outcomes & Results: The main incidents related to legal decisions (for example, power of attorney, will-making), as well as decisions involving consent for medical treatment, discharge, accommodation, and business/financial decisions. In all but one of the incidents recounted, the issues centred on a situation of conflict between the person with aphasia and their family, friends or with the multidisciplinary team. The roles taken by the speech pathologists ranged from those expected within a speech pathology scope of practice, such as that of assessor and consultant, to those which arguably present dilemmas and conflict of interest, for example, interpreter, advocate. The assessment practices involved some standardized testing, but this was stressed by all participants to be of lesser importance than informal observations of function. Speech pathologists emphasized the importance of multiple observations, and multimodal means of communication. Conclusions: & Implications: The findings indicate that speech pathologists are currently playing an active role when questions arise regarding capacity for legal and related decision-making by people with aphasia. At the same time, the findings support the need for further research to develop guidelines for practice and to build educational experiences for students and novice clinicians to assist them when they engage with the complex case management issues in this area. (Contains 5 tables.)