Structural MRI is a key tool in the clinical assessment of Alzheimer's disease (AD). It helps detect early signs of the disease, such as atrophy in the medial temporal lobe, which is a valid diagnostic marker for mild cognitive impairment (MCI). Structural MRI is also used in diagnosing other dementias, aiding in differential diagnosis. Atrophy rates of whole brain and hippocampus are sensitive markers of neurodegeneration and are increasingly used as outcome measures in clinical trials. Large studies are investigating other imaging and non-imaging markers for diagnosis and monitoring. Standardization of methods and development of automated algorithms will enhance the utility of structural imaging. Structural MRI markers are valid for early diagnosis of AD, with hippocampal atrophy being the best established. These markers are also used in diagnostic criteria for non-AD dementias. MRI-based measures of atrophy correlate with cognitive performance and are used to assess disease-modifying drugs. Structural MRI is essential for early diagnosis and monitoring of AD progression. It is also useful in differentiating AD from other dementias. The use of structural MRI in clinical trials is increasing, with atrophy rates being used as surrogate outcomes. The integration of imaging and cerebrospinal fluid markers could improve diagnosis and monitoring. Structural MRI is a critical component of AD diagnosis, providing insights into disease progression and aiding in the development of treatments.Structural MRI is a key tool in the clinical assessment of Alzheimer's disease (AD). It helps detect early signs of the disease, such as atrophy in the medial temporal lobe, which is a valid diagnostic marker for mild cognitive impairment (MCI). Structural MRI is also used in diagnosing other dementias, aiding in differential diagnosis. Atrophy rates of whole brain and hippocampus are sensitive markers of neurodegeneration and are increasingly used as outcome measures in clinical trials. Large studies are investigating other imaging and non-imaging markers for diagnosis and monitoring. Standardization of methods and development of automated algorithms will enhance the utility of structural imaging. Structural MRI markers are valid for early diagnosis of AD, with hippocampal atrophy being the best established. These markers are also used in diagnostic criteria for non-AD dementias. MRI-based measures of atrophy correlate with cognitive performance and are used to assess disease-modifying drugs. Structural MRI is essential for early diagnosis and monitoring of AD progression. It is also useful in differentiating AD from other dementias. The use of structural MRI in clinical trials is increasing, with atrophy rates being used as surrogate outcomes. The integration of imaging and cerebrospinal fluid markers could improve diagnosis and monitoring. Structural MRI is a critical component of AD diagnosis, providing insights into disease progression and aiding in the development of treatments.