Frontotemporal lobar degeneration (FTLD) is a heterogeneous syndrome characterized by a progressive decline in behaviour or language associated with degeneration of the frontal and anterior temporal lobes. FTLD can be classifi ed into three clinical syndromes based on the early and predominant symptoms: behavioural variant frontotemporal dementia (bvFTD); semantic dementia (SD); and progressive non-fl uent aphasia (PNFA). Patients with bvFTD present with marked changes in personality and behaviour such as disinhibition, apathy, loss of sympathy, compulsive behaviours, hyperorality. Neuroimaging studies have highlighted frontal atrophy, hypometabolism and hypoperfusion. SD is characterized by a fl uent anomic aphasia and behavioural changes with degeneration of the anterior temporal lobes. Patients with left-sided SD present with progressive loss of word knowledge and meaning about words, objects and concepts. Patients with PNFA present slow, effortful speech, impaired production and comprehension of grammar. PNFA is associated with atrophy, hypometabolism and hypoperfusion of the left perisylvian area. However, overlap between the syndromes can occur, particularly later in the course. In the absence of defi nitive biomarkers, the diagnosis is dependent on clinical symptoms. A new diagnostic criterion of bvFTD was published in 2011. Identifi cation of the syndrome ' s core symptoms is important in clinical diagnosis.