PROBLEM: The effects of acute upper-body (UB) and lower-body (LB) resistance exercise with blood flow restriction (BFR) on vascular function are unknown. METHODS: Vascular function was assessed in resistance-trained individuals (n=12) using venous occlusion plethysmography with five minutes of occlusion at 220mmHg to induce reactive hyperemia. Forearm blood flow (FBF) and area under the curve (AUC) were assessed at Rest, and during recovery at 15 (R15) and 45 (R45) minutes. BFR was applied at a pressure of 40% arterial occlusion pressure during each exercise, and released for 2 minutes between exercises. A 2x2x3 repeated measures ANOVA was used to examine the effects of condition (BFR, non-BFR) and group (UB, LB) across time (Rest, R15, R45) on vascular function. RESULTS: There were no 3-way interactions for any variable. There was a significant (p=0.001) group by time interaction for FBF (UB: Rest: 2.8±1.2ml/100ml/min; R15: 9.3±4.5ml/100ml/min; R45: 5.3±2.7ml/100ml/min; LB: Rest: 3.3±2.0ml/100ml/min, R15: 4.3±2.5ml/100ml/min, R45: 4.2±2.2ml/100ml/min) such that FBF was elevated at R15 compared to Rest, and was higher after UB than LB at R15. There was also a significant (p=0.02) group by time interaction for AUC (UB: Rest: 65.1±21.6ml/100ml/min, R15: 144.7±50.2ml/100ml/min; R45: 91.0±27.8ml/100ml/min; LB: Rest: 61.9±10.3ml/100ml/min; R15: 113.1±32.4ml/100ml/min, R45: 88.6±32.3ml/100ml/min) such that it was augmented at R15 and R45 compared to Rest, with greater augmentation at R15 after UB compared to LB. CONCLUSIONS: While there were no differences between BFR and non-BFR, our data demonstrate that acute upper-body resistance exercise has a greater effect than acute lower-body resistance exercise on vascular function.