This study explored the potentially beneficial effect of explicit verbalization on the attentional performance in patients with closed head injury (CHI) in both distracting and nondistracting environments. Ten patients with CHI and 10 normal controls were recruited. The findings indicated that in the absence of distractors, the two groups did not differ significantly on the total actual time of off-task behaviour. When distractors were present, the patients performed worse than their controls; whereas verbalization tended to reduce total actual time of off-task behaviour in patients more than normal controls (z=1.965, p=.049), the controls were at ceiling under the verbalization condition. Although the findings must be considered tentative because of this ceiling effect and the small sample sizes, our results do suggest that patients with CHI benefit more from self-instructional cues in a complex and distracting environment.