The management of post-radiation wound breakdown over the posterior cervico thoracic region can be a challenging task for a surgeon. The aim of the treatment is to produce a well vascularized and a low tensile flap which will close a large defect. We describe the use of the lower trapezius flap to reconstruct the wound breakdown and to obtain stable tissue coverage in a patient with post- radiation necrosis. This flap minimizes the disruption of the scapula-thoracic function while preserving the range of movement over the shoulder. From the literature review, it was noted that the dorsal scapular artery (DSA) and transverse cervical artery (TCA) aid in the blood supply to the trapezius muscle and prevent local necrosis during rotation of the flap. The trapezius flap is widely accepted because of the minor donor site morbidity, large arc of rotation and adequate blood supply.