Abstract Background: Breast cancer-related lymphedema of the upper extremity is a fearful annoying complication for axillary clearance in breast cancer survivors. Preservation of upper extremity lymph nodes could help in reduction of incidence of the patients complaining of post axillary clearance lymph-edema. Aim of Study: To evaluate the role of focused ultrasound on lateral group of axillary lymph nodes in evaluation of clinically palpable axillary lymph nodes thus sparing the non-suspicious lateral group by ultrasound and prevention of upcoming lymphedema. Patients and Methods: This prospective study was con-ducted on fifty patients with T1 and T2 breast cancer and pathological axillary lymph nodes by ultrasound. They were scheduled for either conservative breast surgery or modified radical mastectomy with axillary clearance. Lateral group of axillary lymph nodes were divided preoperatively by focused axillary ultrasound into 2 groups. Group A included non-suspicious lateral axillary lymph nodes while group B included suspicious lateral axillary lymph nodes. During axillary dissection, the lateral group of axillary nodes (lying lateral to the thoracodorsal pedicle) was sent separately for histopatho-logical assessment (paraffin). Results: In Group A, 40 patients had a free lateral group by focused axillary US. By postoperative histopathology examination, 37 of them were confirmed free and only 3 cases proved to have metastatic deposits. While in group B, 10 patients had suspicious lateral group by focused axillary US. By postoperative histopathological examination, 8 of them had metastatic deposits and only 2 cases were free of the lateral group. So we concluded that the sensitivity of focused ultrasound of lateral group of axillary lymph nodes was 72.73%, the specificity was 94.87% and the accuracy was 90% in patients who had already suspicious lymph nodes by axillary US. Conclusion: Focused ultrasound of lateral group of axillary lymph nodes has moderate sensitivity, high specificity and accuracy. Sparing of free lateral group in patients with breast cancer could be a helpful surgical procedure aiming to reduc-tion of the rate of upper extremity lymphedema.