Objective: To assess the number and nature of complications during the acute phase following traumatic spinal cord injury and to explore the relationship between number of complications and length of hospital stay. Design: Multi-centre prospective cohort study. Patients: A total of 54 patients with traumatic spinal cord injury, referred to 3 level 1 trauma centres in The Netherlands. Methods: The number and nature of complications were registered weekly from September 2009 to December 2011. Results: A total of 32 patients (59%) had 1 or more medical complications. The most common complications were pressure ulcers (17 patients, 31%) and pulmonary complications (15 patients, 28%). Patients with 3 or 4 complications had significantly (p<0.01) longer hospital stays (58.5 [32.5] days) compared with those with 1 or 2 complications (33.1 [14.8] days) or no complications (21.5 [15.6] days). Conclusion: Complications, particularly pressure ulcers and pulmonary complications, occurred frequently during the acute phase following traumatic spinal cord injury. More complications were associated with longer hospital stays. Despite the existence of protocols, more attention is needed to prevent pressure ulcers during the acute phase following traumatic spinal cord injury for patients in The Netherlands.