Systemic autoimmune diseases, such as vasculitis and collagen diseases, are characterized by chronic inflammation. Mutual interrelationship between angiogenesis and chronic inflammation has already been demonstrated. The aim of the study was to examine the effect of sera from patients with systemic autoimmune diseases on angiogenesis induced by human mononuclear cells. The study population consisted of 43 patients with a systemic autoimmune disease associated with pulmonary manifestations, divided into three groups: 14 with Wegener's granulomatosis (WG), 13 with systemic sclerosis (SS), and 16 with collagen vascular diseases (CVD) such as rheumatoid arthritis, systemic lupus erythematosus, and dermatomyositis. The control group consisted of 15 healthy volunteers. Clinical status was evaluated using a questionnaire. Standard chest radiographs were performed in all patients. Pulmonary function tests were performed according to the ERS standards. An animal model of a leukocyte-induced angiogenesis assay was used as an angiogenic test. Sera from WG and CVD patients significantly stimulated angiogenesis compared with healthy subjects (P<0.001). On the other hand, sera from healthy donors exerted a proangiogenic effect compared with PBS. In contrast, sera from SS patients significantly (P<0.001) inhibited angiogenesis compared with sera from healthy subjects and PBS. Proangiogenic effect of sera from systemic diseases patients depended on radiological changes. No significant correlation between a degree of dyspnea or functional pulmonary tests and the number of new vessels or angiogenesis index was found. Sera from patients with systemic autoimmune diseases and healthy people constitute the source of mediators modulating angiogenesis. These modulatory effects differ depending on the disease entity.