Long-term follow-up data indicate that the systemic vasculitides are chronic relapsing diseases with high morbidity. It is therefore of paramount importance to distinguish activity, which requires cytotoxic or immunosuppressive therapy, from damage requiring rehabilitation. Damage due to underlying disease or treatment highlights the need for more effective, less toxic treatment regimens. An integrated package for clinically based assessment of disease activity in systemic vasculitis, the Vasculitis Integrated Assessment Log, has been accepted for further evaluation and implementation by the European Community Study Group for use in therapeutic trials. The added value of serologic tests and inflammatory markers in clinical assessment is becoming more clear, and unsuspected disease activity has been revealed by biopsy and imaging of standard sites or affected areas. Integration of these data should enable characterization of high- and low-risk patient subgroups to determine specific therapies.