Vascular endothelial growth factor (VEGF) is an angiogenic cytokine which has been reported to be important in the pathogenesis of rheumatoid arthritis (RA). In this study, the serum level of VEGF was measured using enzyme-linked immunosorbent assay in 17 patients with systemic lupus erythematosus, 49 patients with polymyositis/dermatomyositis (PM/DM), 40 patients with systemic lupus erythematosus, 49 patients with polymyositis/dermatomyositis (PM/DM), 40 patients with systemic sclerosis (SSc), 11 patients with RA and 20 control subjects. The VEGF level was 184 +/- 62 pg/mL (mean +/- SD) in the serum of normal individuals. The mean VEGF levels in the patients with PM/DM or RA were significantly higher than in the normal controls. In 21 of the 49 patients with PM/DM and nine of the 11 patients with RA, the serum VEGF level was considered to be elevated. In patients with SSc, those with diffuse cutaneous SSc showed elevated VEGF levels in comparison with normal controls. An elevated serum VEGF level was correlated with the frequency of lung fibrosis and reduced vital capacity in the patients with SSc.