Introduction Vascular access has traditionally been gained from the femoral vessels, however, a ‘radial-first’ approach has become increasingly popular and resulted in lower complication rates and reduced healthcare costs. A “superior” approach has been reported for electrophysiology (EP) studies but is associated with an increased risk. To provide comprehensive anatomical evidence that the vessels of the arms are suitable for use during EP procedures, as assessed by vascular ultrasound. Methods A portable ultrasound device was used to measure the diameter of the brachial artery, brachial, basilic & cephalic veins on the left and right upper limbs of 63 healthy volunteers. A subgroup of 15 volunteers had additional measurements taken with a tourniquet. Results The basilic vein had the largest diameter with a median of 4.6 mm and 4.5 mm (right and left diameter, respectively), followed by the cephalic (median of 3.1 and 3.0 mm) and the brachial vein (median of 2.8 mm). 100% of volunteers had at least one vein that was equal to a 3 mm diameter (which would allow for an 8F sheath), with 98% having 2 suitable veins and >80% having 3 suitable venous vessels. More than 90 % had a suitable diameter for both the right and left brachial artery. There was no correlation between BMI, height, weight, but men had significantly larger basilic veins and brachial arteries (p<0.05). Conclusion We demonstrate the anatomic evidence that the vessels in the arm(s) are capable of housing the size of sheath commonly used in the EP lab.