An investigation of the impact of axillary surgery on arm morbidity in patients who underwent sentinel lymph node biopsy (SLNB), axillary clearance in a one-step procedure, and axillary clearance in a two-step procedure, respectively, was performed. Over a period of 2 years 438 patients with invasive breast carcinoma or carcinoma in situ underwent SLNB at our clinic. Of these 393 were interviewed on symptoms of swelling, numbness, pain, reduced strength, reduced mobility and fatigue more than 1 year postoperatively. Using a standardised symptom score system postoperative morbidity was registered and differences between the patients were compared in a logistic regression analysis. Of the 393 patients who received the questionnaire 370 responded (94%). The mean follow-up was 23.5 months (range 12-37). SLNB resulted in significantly lower arm morbidity than axillary clearance. Doing stepwise logistic regression of the data the two-step axillary clearance represented the most important influential factor of the development of arm morbidity symptoms of swelling and numbness.