Background: Increased attention in the field of speech-language pathology is directed towards evidence-based treatment, particularly with regard to neurogenic communication disorders. Aims: The paper describes the development of an evidence-based aphasia clinic. Core principles of the clinic are the use of language treatment techniques that have support in efficacy data, and the objective measurement of treatment effectiveness. Main contribution: Care paths for aphasia treatment are developed according to levels of evidence (Class I, II, III evidence); cognitive neuropsychological and life participation models; and the World Health Organisation International Classification of Health, Disability and Function (ICF). Multi-layered assessments are obtained at the ICF impairment and activity/participation levels throughout treatment (i.e., weekly treatment probes, monthly discourse probes, and biannual aphasia and neuropsychological assessments). Weekly multidisciplinary staffings address patient progress. The paper discusses limitations and challenges of addressing treatment effectiveness and efficacy within a typical outpatient clinical setting. Conclusions: The principles of evidence-based aphasia therapy and single-subject methodology can be applied in routine clinical rehabilitation settings.