Background: Axillary Web Syndrome (AWS) is characterized by axillary pain radiating down the ipsilateral arm, shoulder range-of-motion limitation, and an axillary web of tissue most obvious on physical examination when the patient tries to abduct her arm. The use of laser as a non-surgical medical treatment modality for assisting the normal processes of healing has increased over the last few years. However, the efficacy of laser in reducing pain or promoting tissue repair remains controversial. Objective: This study was undertaken to determine the effect of low-level laser therapy on axillary web syndrome post mastectomy. Patients and Methods: This study included forty female patients who underwent mastectomy and received their treatment in Tagamoo branch of National Cancer Institute. Their ages ranged 40 to 55 years and body mass index ranged 25 to 30 (kg/m²). The patients were selected from Medical Oncology Department, National Cancer Institute, between January 2019 to June 2019. Results: The results of this study revealed that Group A and Group B showed significant improvement in shoulder mobility (Flexion, Abduction and External rotation) and decrease of pain but by comparison between the two groups, group A showed greater improvement than Group B. Conclusion: It could be concluded that low level laser in addition to traditional therapy and medical therapy can improve shoulder mobility and decrease pain more than using only traditional and medical therapy.The result of this study supported the expectation that Low Level Laser had a position effect on axillary web syndrome.