SummaryA detailed analysis was undertaken to study the incidence of deep vein thrombosis (DVT), pulmonary embolism (PE), and death during the initial hospitalisation after traumatic spinal cord injury (SCI). The National Spinal Cord Injury Statistical Center supplied data on 1419 subjects with acute injuries hospitalised between October 1, 1986 andJune 9,1989. The incidence of PE was 4'6% (4'3% for paraplegia and 4'8% for quadriplegia) and 14·5% for DVT ( 15·9% for paraplegia and 12 ' 5% for quadriplegia). Fifty two patients (3'7%) died during their initial hospitalisation. Age, gender, and quadriplegia were not statistically significantly correlated with the development of DVT, while motor complete lesion was a better predictor of DVT than a complete lesion. The highest incidence of DVT was 22·9% in patients with motor complete paraplegia, while the lowest incidence was 9·3% in patients with motor incomplete quadriplegia. The only significant predictor for PE was age. Mortality was associated with increased age, PE, quadriplegia, and complete lesions. The highest incidence of death was /4·0% in patients :? 40 years of age with quadriplegia and the lowest incidence of death was 0'37% in patients < 40 years of age with paraplegia. This study emphasises the need for careful analysis and detailed stratification when designing or interpreting SCI research with DVT, PE, and mortality. Completeness of lesion, age, and category of impairment, whether quadriplegia or paraplegia, are appropriate strata to select.