The authors identified neuropsychological tests appropriate for use in monitoring delirium severity in elderly patients. Ten elderly patients were administered a battery of tests while they were delirious and later during their recovery. All of the measures showed significant improvement across the two occasions (P < 0.05). Examination of components of variance suggests that modified versions of the Forward Digit Span, Similarities, or Oral Sentence Spelling tests or a combination of Forward Digit Span and Similarities or Oral Sentence Spelling are likely to be most effective in monitoring delirium severity.