Acute hamstring rupture is an uncommon event often occurring during high impact sports. Such events have not been previously reported during neurological rehabilitation. This case report describes a 30 year-old Chinese male presenting in a minimally responsive state 5 years after a severe traumatic brain injury. He was tetraplegic and bed-bound with spasticity involving all four limbs and flexion contracture of the right knee. During an episode of inpatient rehabilitation, he developed acute swelling and bruising of the posterior proximal thigh region associated with fever, tachycardia and diaphoresis. MRI showed a large soft tissue rim-enhancing mass in the right proximal hamstring muscle. During surgical exploration, complete rupture of the right semi-membranosus muscle was found without evidence of pus. The possible causative factors of hamstring rupture in this subject and a brief literature review are discussed. To the authors' knowledge, this is the first such reported case.