Prior studies have shown racial and gender differences with respect to maturation of arteriovenous fistulas. Women and minorities have lower maturation rates for unclear reasons. Small arterial diameter and high brachial artery bifurcation (HBB) are also implicated in reduced maturation rates. We sought to correlate differences in upper extremity arterial anatomy to race and gender. All upper extremity vascular mapping ultrasounds from 2013 to 2014 were retrospectively reviewed. A total of 509 arms in 284 patients were evaluated. Men had significantly higher mean arterial diameters than women at the elbow brachial (4.7 vs 3.9 mm, P < 0.01) and wrist radial arteries (2.1 vs 1.9 mm, P = 0.03). There were 20 (7%) patients with HBB of at least one arm, and 7 (2.5%) patients with bilateral HBB. African-American patients had significantly higher rates of both unilateral HBB (15.9% vs 5.4%, P = 0.02) and bilateral HBBs (9.1% vs 1.3%, P = 0.01). In conclusion, men had significantly larger arteries than women, and African-Americans had a higher rate of HBB than non-African-Americans. Consideration should be given for routine preoperative ultrasound to assess arterial anatomy before arteriovenous fistulas creation, particularly in women and in African-Americans.