Objective: Executive functions in activities of daily living (ADL) were investigated in 10 patients with frontal lobe lesions after a mild to severe closed head injury (CHI). Method: The CHI patients were compared to 12 normal controls with a neuropsychological test battery, a script recitation task and a realistic simulation of complex multitask ADL (planning and preparing a meal). Results: Though the CHI patients were significantly slow on one test and subject to interference on an attention test with parametric testing, the groups did not differ on any neuropsychological test with non parametric testing. However, the CHI patients manifested marked anomalies in the meal preparation task. While small sequences of actions were easily produced, large action sets could not be correctly executed. Conclusion: An outstanding deficit in strategic planning and prospective memory appears to be an important underpinning of the impairment of ADL observed in CHI patients with frontal lobe lesions.