Dementia with Lewy bodies (DLB) is one of the most common causes of dementia, after Alzheimer's disease (AD) and vascular dementia. Its diagnosis remains a challenge for the clinician because of the variety of clinical presentations and comorbidities. The diagnosis is based on clinical criteria such as cognitive fluctuations, visual hallucinations, progressive cognitive impairment, Parkinsonian signs and REM sleep behavioral disorder. Although not specific, biomarkers are helpful for increasing the likelihood of LBD diagnosis and for differentiating LBD from other differential diagnoses such as Parkinson's disease with dementia and Alzheimer's disease. Clinicians should be aware of LBD clinical features and actively look for them in patients with cognitive symptoms, take into consideration the often-associated co-pathologies and to optimize patient's management.