The endothelial glycocalyx is a layer comprised of proteins and carbohydrates on the luminal surface of vascular endothelial cells, thought to have an important role in the health and function of the endothelium. Disrupted by various pathophysiological conditions and linked with clinical outcomes, it is increasingly recognized as an early indicator of endothelial injury and a potential marker of vascular injury. In this review, we discuss current methods of assessment (including novel optical approaches), evidence for its use as a marker of vascular disease and its potential role in relation to microalbuminuria and glomerular endothelial dysfunction. Therapeutic strategies for restoration of the glycocalyx following injury are also explored.