Alzheimer's disease (AD) is the most common neurodegenerative disorder and the leading cause of major neurocognitive disorder in older adults. Its diagnosis has evolved from clinical to clinico-biological criteria, integrating biomarkers such as beta-amyloid and phosphorylated tau in cerebrospinal fluid or specific positron emission tomography (PET) imaging. Recent therapeutic advances, including anti-amyloid immunotherapies, highlight the need for early and accurate diagnosis. Clinical presentation is heterogeneous and may include amnestic or non-amnestic forms. Diagnosis should be suspected in patients with progressive cognitive decline and confirmed through neuropsychological assessment and biomarker testing. Blood-based biomarkers are promising but not yet validated for routine use. Magnetic resonance imaging (MRI) is recommended for all patients with recent cognitive decline. The role of general practitioners in early detection is critical. These recommendations, developed by the French federation of memory clinics, provide guidance on diagnosis stages, biomarker indications, first-line assessments, referral criteria, and communication of diagnosis. They aim to standardize clinical practice and support timely, individualized care.