Seroma formation after axillary lymphadenectomy is common. We performed a randomised controlled trial comparing seroma rate and volume after axillary lymphadenectomy with and without use of drains. In this study, there was no difference in incidence of seroma formation between patients who did and did not have a drain inserted after axillary lymphadenectomy for breast cancer. Undrained patients, however, had larger volume seromas of longer duration which required more aspirations. There was a tendency for undrained patients to have fewer complications when compared to patients with drains.