Ten women with unilateral arm lymphedema after axillary clearance (radical mastectomy) and radiotherapy for breast cancer received 16 treatment sessions with Low Level Laser Therapy (LLLT) over 10 weeks and seven patients were followed for 36 months. The effect of LLLT was monitored by arm circumference, plethysmography, tonometry, bioimpedance and a questionnaire dealing with subjective symptoms. After treatment, edema volume (both extracellular and intracellular) was decreased, the tissue (except for the upper arm) progressively softened or approached a normal texture, and the patients reported improvement in aches/pains, tightness, heaviness, cramps, pins/needles, and mobility of the arm. Skin integrity was also improved and the index for risk of infection decreased.