Early identification and rapid treatment of red tag patients may decrease morbidity and mortality. We examined the clinical characteristics, etiologies and one week mortality rate of red tag (life threatening and potentially life threatening illness) patients at the Hospital Universiti Sains Malaysai (HUSM). A cross-sectional study was conducted at the Emergency Department of the HUSM from 1 August 2006 to 31 January 2007; 440 eligible patients were analyzed. The group had a mean age of 47.2 +/- 22 years, with 67.3% of the patients being male. Twenty-three percent were trauma cases with motor vehicle accident being the major mechanism of injury. Fifty-four percent of the cases had cardiac related illnesses. The mean duration of stay in the Emergency Department (ED) was 3.9 +/- 1.5 hours. The survival rate at one week was 76.6%. The non-trauma group comprised 74.0% of death cases. Acute coronary syndrome and road traffic accidents comprised 22.0% of total death cases at one week. Red tag patients constitute a large proportion of ED cases and may remain in the ED for significant periods of time.