Language led dementia, also known as primary progressive aphasia (PPA), is an emerging area of practice in speech and language therapy. Given that the diagnosis centres around the key diagnostic feature of language, whereby language impairment is the most prominent clinical feature impacting on daily living, it seems logical that speech and language therapists would be involved in the diagnosis and management of people living with this type of dementia. The authors start by emphasising the important role of SLTs in differentially diagnosing between the three PPA variants (semantic, logopenic and non-fluent agrammatic) in view of the differing underlying pathologies and potential for people to be involvement in clinical trials targeting. They also describe using assessment to measure deterioration and, perhaps most importantly, to plan therapy interventions. They highlight the value of many assessment batteries developed for non-progressive aphasia, such as the Boston Diagnostic Aphasia Examination (BDAE) and the Western Aphasia Battery (WAB) but also provide examples of new PPA specific tools such as the Sydney Language Battery (SydBat) and the Repeat and Point Test. In-depth assessment may require the use of a range of assessments and the authors list both formal and informal approaches to domains of language known to be affected in PPA such as lexical retrieval, semantics, single word comprehension, syntax, repetition, motor speech and fluency, written language and non-linguistic cognitive abilities. Few clinical guidelines or pathways currently exist, even within local services, and speech and language therapists are often using informal assessment or tools designed for people with stroke aphasia. This article presents a timely review of the relevant assessment tools, it also highlights the breadth of the role of speech and language therapists and spreading the word amongst the wider health community.