Michelle Palazzolo, 35, was arrested after investigators say she ran a red light at Rocky Run Parkway and Concord Pike and crashed into a Toyota Prius.
The driver of that vehicle, a 72-year-old man from Newark, Delaware, was taken to a hospital where he later died.
His name has not yet been released.
Delaware State Police say Palazzolo showed signs of impairment at the time of the crash.
Palazzolo has been charged with vehicular homicide 2nd degree, driving under the influence, driving under the influence of alcohol, failure to have required insurance and failure to stop at a red light.