Cardiopulmonary bypass via the axillary artery is frequently used especially in aortic dissections. With an increased use of this technique problems were recognized too. We describe the technical problems and complications associated with axillary artery cannulation. Sixty-five patients underwent cannulation of the axillary artery. The indication for operation was acute aortic dissection type A in 57%, chronic aortic dissection in 8%, aortic aneurysm in 18%, pseudoaneurysm in 3%, and others in 14%. Technical problems and complications occurred in 14%, and in 11% the perfusion had to be switched to either femoral (n=5) or aortic cannulation (n=2). Arterial damage or dissection of the axillary artery or the aorta occurred in 0% of the sidegraft technique, whereas they were found in 9% with direct cannulation (P=n.s.). Cannulation problems or insufficient CPB flow due to a narrow vessel occurred in 0% of the sidegraft technique, whereas they were found in 4% with direct cannulation (P=n.s.). Malperfusion in aortic dissections occurred in 20% of the sidegraft technique, whereas they were found in 0% with direct cannulation (P=0.016). No postoperative complications related to axillary cannulation which were evaluated by clinical examination, such as brachial plexus injury, axillary artery thrombosis or local wound infection were observed. Although axillary artery cannulation is an attractive alternative to femoral cannulation there needs to be an alertness for technical problems. Different complications occur with either direct cannulation or the sidegraft technique and at present it remains the surgeons preference which technique for axillary artery cannulation is used.