The importance of axillary dissection as part of the primary surgical procedure in the treatment of operable cases of carcinoma of the breast is established. The morbidity of this procedure, however, is less well documented. A study of 126 women who had had full axillary dissection as part of their initial surgical treatment was undertaken to assess their degree of morbidity in terms of numbness, pain, weakness, swelling, and stiffness. Seventy per cent of cases complained of numbness, 33% of pain, 25% of weakness, 24% of limb swelling, and 15% of stiffness. Objective measurements confirmed decreased sensation in 81%, weakness in 27%, swelling in 10%, and stiffness in 10%. In no case were these symptoms described as severe, though they did have an effect upon the daily lives of 39%. The side effects of full axillary dissection are common and all women should be warned of them prior to surgery; however they are usually mild and therefore should not preclude this procedure as a part of definitive surgical treatment.