Suicide becomes a serious problem in today's society and hanging is a common method of suicide. We want to find the factors which can predict the final functional outcomes of these cases. All patients who presented to Accident and Emergency Department (ED) of the National Cheng Kung University Hospital from 1st January 2005 to 31th December 2013 with a hanging injury were included in this study. All cases were divided into good outcome group and bad outcome group according to Glasgow Outcome Scale (GOS). Data was analyzed by Mann-Whitney test and chi-square test. Glasgow Coma Scale (GCS) < 3, pupil dilation and no pupillary light reflex both at the scene and ED were the factors to indicate poor functional outcome. Out-hospital cardiac arrest (OHCA), acidosis (pH < 7.2) and the need for intubation once arriving at ED were also related to poor functional outcome. OHCA cases all had poor functional outcome. GCS, pupil size, pupillary light reflex, OHCA and acidosis are useful as prognostic factors. GCS = 3 lead to a very poor outcome. However, the functional outcome seems good in patients with GCS>3. There parameters can help to predict the outcome before treatment.