This consensus document updates the Mannheim Carotid Intima-Media Thickness and Plaque Consensus (2004–2006–2011) and addresses the standardization of carotid intima-media thickness (IMT) measurements and the classification of early atherosclerotic lesions. IMT is a surrogate endpoint for cardiovascular outcomes in clinical trials, while carotid artery plaque adds to the assessment of cardiovascular risk. The document provides detailed guidelines for ultrasound characterization of IMT and plaque, including definitions, physical and structural basics, standards for image acquisition, and methodology. It emphasizes the importance of distinguishing between IMT and plaque, as they represent different phenotypes with distinct risk implications. The document also outlines the use of IMT and plaque in clinical practice and research, including reference values and guidelines from various societies. Standardized methods for IMT and plaque measurements are recommended to ensure homogenous data collection and analysis, enhancing the power of clinical trials and facilitating meta-analyses.This consensus document updates the Mannheim Carotid Intima-Media Thickness and Plaque Consensus (2004–2006–2011) and addresses the standardization of carotid intima-media thickness (IMT) measurements and the classification of early atherosclerotic lesions. IMT is a surrogate endpoint for cardiovascular outcomes in clinical trials, while carotid artery plaque adds to the assessment of cardiovascular risk. The document provides detailed guidelines for ultrasound characterization of IMT and plaque, including definitions, physical and structural basics, standards for image acquisition, and methodology. It emphasizes the importance of distinguishing between IMT and plaque, as they represent different phenotypes with distinct risk implications. The document also outlines the use of IMT and plaque in clinical practice and research, including reference values and guidelines from various societies. Standardized methods for IMT and plaque measurements are recommended to ensure homogenous data collection and analysis, enhancing the power of clinical trials and facilitating meta-analyses.