We aimed to prospectively assess limb volume change (LVC) and associated symptoms in patients with melanoma undergoing sentinel lymph node biopsy and/or therapeutic lymph node dissection. Limb volume was measured preoperatively and postoperatively at 6 and 12 months using a perometer (1000 mol/l). LVC was calculated and used to define three groups: less than 5%, 5-10%, and greater than 10%. A 19-item lymphedema symptom questionnaire was administered at baseline, 6, and 12 months. One hundred and eighty-two patients were enrolled. Twelve months after axillary surgery, 9% had LVC 5-10% and 13% had LVC greater than 10%. Twelve months after inguinofemoral surgery, 10% had LVC 5-10% and 13% had LVC greater than 10%. There was a significant seven- to nine-fold increase in symptoms for patients with LVC greater than 10% compared with those with LVC less than 5% (P<0.05). On multivariate analysis, therapeutic lymph node dissection versus sentinel lymph node biopsy (odds ratio=3.18; P<0.01) and borderline significance for lower-extremity versus upper-extremity procedures (odds ratio=1.72; P=0.07) were associated with LVC greater than 5%. LVC greater than 5% is common at 12 months following nodal surgery for melanoma and is associated with symptoms. Informed consent for melanoma patients undergoing lymph node surgery should include a discussion of the risks of postoperative lymphedema.