In response to the need for a disease severity measurement, the American Venous Forum committee on outcomes assessment developed the Venous Severity Scoring system in 2000. There are three components of this scoring system, the Venous Disability Score, the Venous Segmental Disease Score, and the Venous Clinical Severity Score (VCSS). The VCSS was developed from elements of the CEAP classification (clinical grade, etiology, anatomy, pathophysiology), which is the worldwide standard for describing the clinical features of chronic venous disease. However, as a descriptive instrument, the CEAP classification responds poorly to change. The VCSS was subsequently developed as an evaluative instrument that would be responsive to changes in disease severity over time and in response to treatment. Based on initial experiences with the VCSS, an international ad hoc working group of the American Venous Forum was charged with updating the instrument. This revision of the VCSS is focused on clarifying ambiguities, updating terminology, and simplifying application. The specific language of proven quality-of-life instruments was used to better address the issues of patients at the lower end of the venous disease spectrum. Periodic review and revision are necessary for generating more universal applicability and for comparing treatment outcomes in a meaningful way.