Structural co-variance refers to the coordinated variation in brain structure across regions, reflecting functional and developmental relationships. This phenomenon is genetically influenced, associated with cognitive and behavioral traits, and changes throughout the lifespan. It partially mirrors functional networks and is linked to neurodegenerative diseases. Structural co-variance is influenced by genetic and environmental factors, and its patterns are associated with various neurological and psychiatric conditions. It is also related to intrinsic brain activity and white matter networks. Research has shown that structural co-variance networks are organized in a 'small-world' manner, with strong correlations within and between brain regions. These networks are influenced by developmental processes, genetic factors, and environmental influences. Structural co-variance is also affected by learning and training, as seen in musicians and individuals with reading difficulties. In healthy aging, structural co-variance patterns change, with some networks showing reduced co-variance while others remain stable. In neurodegenerative diseases like Alzheimer's and schizophrenia, structural co-variance is altered, reflecting disease-related changes in brain connectivity. Other conditions, such as epilepsy, autism, and mood disorders, also show altered structural co-variance patterns. Structural co-variance provides insights into brain development, function, and disease mechanisms. Future research aims to better understand the cellular and molecular mechanisms underlying structural co-variance and to improve the clinical utility of structural MRI in diagnosing and treating neurological and psychiatric disorders.Structural co-variance refers to the coordinated variation in brain structure across regions, reflecting functional and developmental relationships. This phenomenon is genetically influenced, associated with cognitive and behavioral traits, and changes throughout the lifespan. It partially mirrors functional networks and is linked to neurodegenerative diseases. Structural co-variance is influenced by genetic and environmental factors, and its patterns are associated with various neurological and psychiatric conditions. It is also related to intrinsic brain activity and white matter networks. Research has shown that structural co-variance networks are organized in a 'small-world' manner, with strong correlations within and between brain regions. These networks are influenced by developmental processes, genetic factors, and environmental influences. Structural co-variance is also affected by learning and training, as seen in musicians and individuals with reading difficulties. In healthy aging, structural co-variance patterns change, with some networks showing reduced co-variance while others remain stable. In neurodegenerative diseases like Alzheimer's and schizophrenia, structural co-variance is altered, reflecting disease-related changes in brain connectivity. Other conditions, such as epilepsy, autism, and mood disorders, also show altered structural co-variance patterns. Structural co-variance provides insights into brain development, function, and disease mechanisms. Future research aims to better understand the cellular and molecular mechanisms underlying structural co-variance and to improve the clinical utility of structural MRI in diagnosing and treating neurological and psychiatric disorders.