The basic premise of symptom validity tests (SVTs) is that appropriate effort can be assessed because the designs of SVT measures are thought to be insensitive to all but the most extreme forms of impairment of memory. In patients with mild traumatic brain injury in particular, it is thought that failure on effort measures consistently reflects poor effort or even conscious exaggeration of symptoms. This study examines the issue of SVT failure as a reflection of cognitive impairment and/or neuropsychiatric impairment by presenting cases of three patients who were given full neuropsychological batteries but in each case failed the Word Memory Test (WMT), a verbal recognition SVT measure. One patient who failed the WMT was probably in the early stages of dementia. The WMT fit the "Genuine Memory Impaired Profile". Two mild traumatic brain injury patients failed the WMT but their patterns of performance suggested that cognitive deficits influenced WMT performance. In determining the validity of neuropsychological test data in the individual case, it is recommended that the examiner consider whether cognitive impairment could affect performance on effort measures and the recommended cut score. Also, it is recommended that examiners use multiple indicators of effort.