Dementia is a complex progressive syndrome characterised by impairment of cognition (including memory, language, visuospatial skills and executive function), changes in personality and diminished activities of daily living. The impact of dementia is enormous and poses a huge challenge to patients, their carers, society at large and health systems around the world, in terms of the direct cost of medical care, social care and unpaid care provided by family members and others. In this review, we combine evidence and clinical opinion, using guidelines and reviews from 2006, 2009 and 2010 to present a practical guide for primary care physicians to the diagnosis, treatment and ongoing care of patients with suspected or diagnosed dementia. This review summarises the epidemiology of dementia syndrome, and offers detailed evidence-based advice on recognition of dementia (including subtyping) and responses to it and its associated symptoms. The roles of neuroimaging and biomarkers are discussed, as are both non-pharmacological and pharmacological therapies.