Study design <p>Retrospective cohort study.</p> Objectives <p>To assess the impact of concomitant traumatic brain injury (TBI) on demographic data, injury characteristics, management choices, access to optimal care, and clinical, neurological and functional outcomes after acute traumatic spinal cord injury (tSCI).</p> Setting <p>18 acute care centers and 12 rehabilitation facilities across Canada.</p> Methods <p>Data for the study was selected from the Rick Hansen Spinal Cord Injury Registry (RHSCIR) from 2004 to 2020 in Canada. The tSCI-alone group was compared with the tSCI+TBI group regarding injury epidemiology, management, and outcomes post-tSCI.</p> Results <p>There were 966 individuals with tSCI+TBI and 3520 individuals with tSCI alone. The latter included older and more predominantly White individuals who typically sustained a less severe tSCI, less often at cervical levels due to falls. While need for surgical spinal cord decompression and spine stabilization was more common in the tSCI-alone group (<i>p</i> = 0.0087), mechanical ventilation was more often required in the tSCI+TBI group (<i>p</i> &lt; 0.0001). In-hospital mortality rate, length of stay in the acute care and rehabilitation centers were greater in the tSCI+TBI group (<i>p</i> &lt; 0.0001). However, both groups had similar changes in the motor scores from admission to discharge from the hospital (<i>p</i> = 0.6096). While both groups had similar frequencies of pain (<i>p</i> = 0.9848), spasticity was more frequent in the tSCI+TBI group (<i>p</i> &lt; 0.0001).</p> Conclusions <p>Our results underscore significant differences between the tSCI+TBI group and the SCI-alone group regarding the injury epidemiology, management and outcomes. Those results suggest that concomitant TBI should be considered a major potential confounder in future SCI research studies.</p>