Shirley Miller, 57, of Penns Ridge Place in Downingtown, has been missing since Tuesday.
At this time, police believe that Miller left the residence on foot by her own free will. There is no indication of foul play.
Rescuers conducted a search by ground and air on Tuesday to find Mill, with no success.
She is described as a white woman standing about 5'3" tall and weighing 110 pounds. She has reddish-brown hair and brown eyes.
State Police are asking anyone who may have seen Miller walking in the area or using any form of public or private transportation to contact them at (484) 340-3241.