Research has suggested that sustaining a traumatic brain injury (TBI) may increase one's risk of developing Dementia of the Alzheimer's Type (DAT) later in life. Several neuropathological models have been proposed to explain the association between TBI and DAT and studies using a neuropsychological deficit profile methodology suggest that the pattern and extent of cognitive decline associated with these conditions are similar. This paper presents a new conceptual model, derived from deficit profile methodology, regarding the relationship between TBI and DAT. This model proposes that, for some individuals, TBI may not lead to true DAT neuropathology, but rather produces a profile of neuropsychological deficits similar to DAT, which increasingly mimics the symptoms of true DAT as the TBI survivor ages. Understanding how TBI may contribute to the development of DAT has important social and medical implications, influencing the direction of prevention efforts and contributing to one's understanding of DAT.