The revised Ghent nosology for Marfan syndrome (MFS) was developed to improve diagnostic accuracy and management. The original criteria, based on clinical manifestations, had limitations, including insufficient validation, applicability in children, and reliance on expensive tests. The revised nosology emphasizes cardiovascular features, particularly aortic root aneurysm and ectopia lentis, as cardinal diagnostic indicators. In the absence of a family history, these two features are sufficient for a definitive diagnosis. If either is absent, a confirmed FBN1 mutation or systemic manifestations are required. A new scoring system is introduced to assess systemic features. FBN1 testing, while not mandatory, is given greater weight in diagnosis. Special attention is given to children and alternative diagnoses in adults. The revised criteria aim to reduce misdiagnosis and improve patient counseling. The new nosology includes specific scenarios for diagnosing MFS in sporadic and familial cases. It also addresses overlapping conditions like Sphrintzen–Goldberg syndrome (SGS), Loeys–Dietz syndrome (LDS), and vascular Ehlers–Danlos syndrome (vEDS), which share features with MFS but have distinct risks and management protocols. The revised criteria also include detailed guidelines for cardiovascular, ocular, and systemic features, as well as management strategies for aortic disease, mitral valve prolapse, and other complications. The goal is to enhance diagnostic accuracy, reduce misdiagnosis, and improve patient outcomes through better risk assessment and follow-up.The revised Ghent nosology for Marfan syndrome (MFS) was developed to improve diagnostic accuracy and management. The original criteria, based on clinical manifestations, had limitations, including insufficient validation, applicability in children, and reliance on expensive tests. The revised nosology emphasizes cardiovascular features, particularly aortic root aneurysm and ectopia lentis, as cardinal diagnostic indicators. In the absence of a family history, these two features are sufficient for a definitive diagnosis. If either is absent, a confirmed FBN1 mutation or systemic manifestations are required. A new scoring system is introduced to assess systemic features. FBN1 testing, while not mandatory, is given greater weight in diagnosis. Special attention is given to children and alternative diagnoses in adults. The revised criteria aim to reduce misdiagnosis and improve patient counseling. The new nosology includes specific scenarios for diagnosing MFS in sporadic and familial cases. It also addresses overlapping conditions like Sphrintzen–Goldberg syndrome (SGS), Loeys–Dietz syndrome (LDS), and vascular Ehlers–Danlos syndrome (vEDS), which share features with MFS but have distinct risks and management protocols. The revised criteria also include detailed guidelines for cardiovascular, ocular, and systemic features, as well as management strategies for aortic disease, mitral valve prolapse, and other complications. The goal is to enhance diagnostic accuracy, reduce misdiagnosis, and improve patient outcomes through better risk assessment and follow-up.