The aim of this study was to assess the relationships between divided-attention deficits and working-memory limitations after severe traumatic brain injury (TBI). Severe TBI patients (n = 43) and controls were given a n-back task of three different load levels, which was performed as a single and a dual task. Patients demonstrated, as expected, a difficulty in dual-task processing and an increased susceptibility to high working-memory load, but dual-task performance and working-memory load did not interact as expected. These results are in accordance with recent findings suggesting that dual-task performance and other working-memory functions represent dissociable although interrelated abilities.