The objective of the study is to examine the relationship between synovial blood flow signals and vascular endothelial growth factor (VEGF) involved in angiogenesis by Doppler ultrasound. Twenty-one patients meeting the diagnostic criteria of the American College of Rheumatology (ACR) were enrolled in this study. Doppler ultrasound signals of blood flow in the wrist synovial membrane were measured and classified into three grades: grade 1 = no flow; grade 2 = mild flow; grade 3 = intense flow. A significant correlation was observed between blood flow signals in the wrist synovial membrane and serum VEGF levels (r = 0.5681, P = 0.0072). These results suggest that the measurement of Doppler ultrasound signals of blood flow in the wrist synovial membrane is useful in the evaluation of angiogenesis.