Since the seminal Pick's description more than a century ago, the interest in Frontotemporal dementias has grown exponentially. Fueled by advances in neuroimaging and biomarkers, progress in the field has brought new insights into clinical categorization, neural correlates of higher brain function and pathological mechanisms of neurodegeneration. Paradoxically, those advances have also brought controversy and challenges, some of which have motivated the inception of new diagnostic criteria for those conditions. This brief review accounts for the historical evolution of these conditions and describes current diagnostic criteria for behavioural and primary progressive aphasia, the two major clinical presentations of frontotemporal dementias.