Angiogenesis is involved in chronic inflammatory joint diseases such as rheumatoid arthritis (RA). Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis. The spondylarthropathies (SpA) are characterized by enthesitis and synovitis, in which blood vessels participate. The objective of this study was to investigate serum VEGF levels and their potential associations with disease activity markers for SpA. Sera were collected from 105 patients with SpA (72 with ankylosing spondylitis (AS), four with psoriatic arthritis (PsA), six with reactive arthritis (ReA), eight with enteropathic arthropathy and 15 with undifferentiated SpA), 50 patients with rheumatoid arthritis (RA) and 64 healthy controls. Disease activity in SpA patients was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and laboratory parameters of inflammation [erythrocyte sedimentation rate (ESR) and C-reactive protein level (CRP)]. Serum VEGF levels were significantly higher in SpA patients (316.4 +/- 215.6 pg/ml) and RA patients (405.2 +/- 366.5) than in controls (217.3 +/- 145.2) (P = 0.003). In SpA patients, serum VEGF levels correlated with disease activity indices (BASDAI: r = 0.22, P = 0.04; ESR: r = 0.3, P = 0.003; and CRP: r = 0.23, P = 0.02). Serum VEGF levels were not associated with presence of extra-articular manifestations or syndesmophytes or with the grade of sacroiliitis. These results suggest that VEGF and therefore angiogenesis may play a role in SpA pathogenesis and may serve as a disease activity marker in SpAs.