Purpose Our previous study has demonstrated an impairment of pulsatile ocular blood flow (POBF) in patients with Graves'ophthalmopathy (GO). Here we further evaluate the haemodynamic change in GO patients after systemic steroid. Methods In a prospective, interventional, consecutive clinical case series, all patients with active and moderately severe GO who underwent systemic steroid treatment were evaluated. The change of POBF and the clinical activity and severity of the disease were assessed. Results In total, 11 patients underwent intravenous methylprednisolone pulse therapy followed by 2-month oral prednisolone therapy. POBF improved from a mean value of 476.5 to 614.7 ll/min (Po0.001) after treatment. Likewise, the mean clinical activity score reduced from 4.8 to 1.6. However, systemic steroid had less effect on the severity of GO. It also revealed that there is a greater improvement of POBF in those with more clinical activity score (44) at the onset. Conclusions Following treatment with systemic steroid we have demonstrated a significant improvement in POBF in patients with GO.