Abstract Background Accessory breasts occur in 0·4–6 per cent of women. They may be asymptomatic or cause pain, restriction of arm movement, cosmetic problems or anxiety. It is currently recommended that all accessory breasts be removed surgically but complications following this procedure have been poorly documented. Methods All patients who presented with axillary accessory breasts between July 1999 and October 2000 were identified from a computer database. A retrospective review of patients listed for excision of accessory breast tissue was undertaken to determine any postoperative complications. Results Women with axillary accessory breasts represented 0·5 per cent of all new referrals. A total of 28 women (80 per cent of those diagnosed) had surgery. Eleven patients experienced postoperative complications; the majority followed operations performed by a trainee. Conclusion Excision of accessory axillary breast tissue was associated with significant morbidity.