Frontotemporal neurocognitive disorder (NCD) (also frontotemporal dementia, FTD) constitutes a leading form of NCD in patients younger than age 65. It can lead to the behavioral-variant frontotemporal NCD (bvFTD) or pure cognitive and language changes, as in primary progressive aphasia (PPA). Although patients with bvFTD have relatively preserved memory and language function (at least early in illness course), they display major deficits in emotional regulation, social behavior, insight, judgment, working memory, and executive functions. Patients with primary progressive aphasia (PPA) most commonly have difficulty with naming and/or word finding. Other common presenting symptoms include hesitancy or nonfluent speech production, motor speech abnormalities (such as dysarthria), impaired language comprehension, and repetition. Primary Progressive Aphasia has itself been divided into three separate subsyndromes: the nonfluent/agrammatic (PNFA or nfvPPA), semantic (SD or svPPA), and logopenic (lvPPA) variants, although the lvPPA variant usually is associated with Alzheimer disease. The FTD syndromes are closely related to and can overlap with corticobasal syndrome (CBS), progressive supranuclear palsy (PSP) and motor neuron disease (MND, also known as amytrophic lateral sclerosis (ALS)). The clinical presentation is determined by the anatomical areas involved and the pathognomonic atrophy. An accurate clinical diagnosis helps to predict probable neuropathology, which is essential for targeted treatment planning. It is important to emphasize that the FTDs are a common cause of dementia with age of onset younger than age 65 years, illustrating that dementia syndromes are not solely the province of geriatric psychiatry. Given the current absence of specific disease-modifying intervention for FTD, psychopharmacology intervention for the many psychiatric symptoms in FTD remains an important clinical priority for these patients, and can result in improved patient function, despite the ultimate progression of the underlying illness. In this chapter, we review the primary symptomatology of these frontotemporal NCD variants, diagnostic and treatment challenges, and comorbidity complexity that needs to be considered in differential diagnosis.