Two head injury patients who experienced the onset and/or exacerbation of post-concussion symptoms (i.e., headache, confusion, and memory difficulty) associated with increased environmental stress are presented. The cases provide insight into the complex interaction between neurological and psychological factors following head injury. Patients should be made aware or cognitive limitations during the recovery period so as to better determine acceptable levels of environmental stress. The development or exacerbation of post-concussion symptoms during convalescence signals the physician that a discrepancy exists between the patient's cognitive capacities and environmental demands. Timely intervention to modify environmental stress would help alleviate problems with post-concussion symptoms.