To review all cases of concurrent vasculitis and solid tumors diagnosed at our Department over a 15-year period and explore evidence that would support the notion of vasculitis being a true paraneoplastic syndrome. We reviewed the records of all patients diagnosed with vasculitis and solid tumors within 12 months of each other and prospectively followed until death or our report. We analyzed the main features and outcome of vasculitis in this setting. We also reviewed all cases published in the French-English literature. Fifteen patients (9 men and 6 women) in whom both vasculitis and solid tumor occurred within the same 12 months were identified. Mean age was 72.5 years (range 58-84). In 7 cases the diagnosis of vasculitis antedated that of cancer, in 6 both processes were synchronously diagnosed, and in 2 vasculitis appeared after cancer diagnosis. The most common vasculitis was cutaneous leukocytoclastic vasculitis (n = 9). Other vasculitides included Henoch-Shönlein purpura (n = 2), polyarteritis nodosa (n = 1), and giant cell arteritis (n = 3). The commonest malignancies were carcinomas of urinary organs (40%), lung (26.7%), and gastrointestinal tract (26.7%). The median followup was 28.4 months (range 1-96). Thirteen of the 15 patients demonstrated concordance of disease activity and treatment response for both cancer and vasculitis. Vasculitis flared heralding tumor recurrence or progression in 7 (46.6%) cases. In our patients, resolution of vasculitis following effective treatment of the putatively linked malignancy, and recurrence of vasculitis heralding tumor recurrence or progression, provide strong evidence for vasculitis being a true paraneoplastic syndrome. Chronic or persistent vasculitis with poor response to usually effective therapy, especially in elderly patients, should raise questions about underlying malignancy.