In order to meet the needs of the high acuity population in today's critical care environment, the role of the Acute Care Nurse practitioner (ACNP) has been adopted by many intensive care units (ICU's) across the country, including specialized neurocritical care units. In this chapter we will provide a brief historical review of the ACNP as well as their function in various ICU settings. Lastly, we will describe the current role of the ACNP in the Neurosciences Critical Care Unit at the Johns Hopkins Hospital as well as future plans and challenges of the role.