AbstractWe describe a patient in whom a brachial arterial cutdown done at the same site for percutaneous transluminal angioplasty immediately after uncomplicated percutaneous brachial coronary arteriography revealed the percutaneous sheath in a deeper, smaller, and more lateral artery than the brachial artery, complicating placement of the guiding catheter. This case illustrates the potential hidden hazard of normal brachial artery bifurcation variants, which may be responsible for some of the potential complications encountered in percutaneous brachial artery catheterization techniques.