A study is reported into the role of virtual environments in the assessment of patients with executive dysfunction. Five patients and five matched controls entered the study. The patients did not differ significantly from normative values on the standard executive dysfunction measure, the Behavioural Assessment of the Dysexecutive Syndrome battery (Wilson, Alderman, Burgess, Emslie, & Evans, 1996); however, care staff reported the patients had problems planning. Patients and controls undertook both real and virtual environment multiple-errand planning tasks. The patients completed significantly fewer errands, and produced significantly worse plans than did controls in both the real and virtual environments. There was a significant correlation between performance in the real and virtual environments. The results suggest that virtual environments may provide a valid means of assessing planning impairments and that there may be patients with executive dysfunction (specifically planning deficits) that may not be detected by the currently available standardized tests.