Purpose: Radiotherapy is a critical component of breast cancer treatment. Many skin reactions ranging from erythema to moist desquamation and ulceration can be induced by high dose external beam radiotherapy. There is no golden standard for treating radiation dermatitis. Glutamine is an amino acid which improved wound healing through its anabolic effects and improvements in wound matrix formation in burn patients. We designed a. study to show effects of glutamine in radiation induced dermatitis.