We report a case of systemic polyarteritis nodosa (PAN) leading to the discovery of an as yet asymptomatic, surgically curable gastric adenocarcinoma. PAN is rarely associated with malignancies and in such cases these are more often malignant haematological diseases than solid neoplasms. The immunopathological findings, the temporal relationship between both conditions, and the spontaneous resolution of vasculitis after tumour removal suggest a paraneoplastic origin of the systemic angitis.