Older adults tend to have poorer outcomes compared to younger adults following moderate-to-severe traumatic brain injury (TBI). Currently, there is a need for research focusing on how elderly TBI has changed as the U.S. population shifts. This study provides a statewide account of moderate-to-severe TBI in regard to injury-related variables and incidence rates in the elderly. Data from Pennsylvania accredited trauma centers collected in the Pennsylvania Trauma Outcome Study between 1992 and 2009 were used in the current study. Incidence rates for TBI were calculated using U.S. Census Bureau estimates for individuals aged 65-90 years (separated into three subgroups: ages 65-73, 74-82, and 83-90 years). In addition, we focused on describing the following injury-related variables: mechanism of injury, injury severity, hospital length of stay, and functional status at discharge. The results indicate that the incidence of elderly TBI has approximately doubled in the past 18 years, and that the increase in elderly TBI is greatest for individuals between the ages of 83 and 90. Furthermore, this age group had the poorest outcomes following TBI. Prevention and awareness of TBI in the elderly is imperative in reducing the likelihood of injury and disability. Continued statewide work is needed to demonstrate trends in elderly TBI nationwide to further add to the knowledge base used for prevention and rehabilitation work.