Microlymphaticovenous anastomoses provide a potential for reducing lymphedema of the upper extremity complicating radical mastectomy or irradiation. Lymphoscintigraphy is a valuable investigative modality in the perioperative evaluation of patients undergoing this surgical procedure. The radionuclide studies provide information regarding structural change and physiologic derangement with a low radiation dose to the patient. It is a simple, painless procedure requiring minimal skill and no surgical intervention. In addition, a reproducible method for preparing a radiocolloid suitable for lymphatic imaging using an approved drug as a precursor has been developed.