The subclavian veins begin at the lateral margin of rib I as continuations of the axillary veins. Passing medially on each side, just anterior to the anterior scalene muscles, each subclavian vein is joined by the internal jugular vein to form the brachiocephalic veins.
The only tributary to each subclavian vein is an external jugular vein.
The veins accompanying the numerous arteries in this region empty into other veins.