Diffuse inflammatory angiitis is seen in extremely varied aetiological and nosological situations. In some cases, the vascular disease represents the only sign of systemic disease. In other cases, it mays be associated with or complicated by diffuse systemic inflammatory conditions. This study analysed 100 cases of inflammatory angiitis with systemic manifestations seen over a period of 7 years in a rheumatology department. Patients with scleroderma, erythema nodosa, Behçet's syndrome and angiitis associated with microbial infectious diseases were excluded from this study. 24 cases in which the angiitis was clinically certain, but in which the vascular lesion was not confirmed histologically were also excluded. The type of histological lesion and the nosological distribution of these 100 cases are described in detail. The results of this analysis confirm the very great variety of the clinical and histological presentations. A number of rare syndromes were observed. Classical periarteritis nodosa only represented 14 per cent of the whole series and only 3 of the 14 cases had a demonstrable aetiology (2 HBs, 1: desensitisation to Candidin). The authors stress the histological diversity of inflammatory angiitis associated with rheumatoid arthritis and systemic lupus erythematosus. All sizes of vessels may be involved and all types of lesions can be observed in these two diseases. The authors also emphasise the lesser known clinical and histological features (stenosing endarteritis of the great vessels in systemic lupus erythematosus) and previously unreported cases (valvular lesions in 2 cases of Mac Duffie's syndrome, progression of 2 cases of delayed urticaria to pressure towards a clinical lupus with unusual laboratory findings).(ABSTRACT TRUNCATED AT 250 WORDS)