Debra Miller, 38, was last seen on Saturday when a neighbor happened to see her bringing in groceries.
There has been no contact with her since.
Police say there was no sign of a struggle in the home and no one has been able to reach Miller on her cell phone.
Family members tell police it is very unusual for her to be out of contact this long.
Miller is described as standing 5'7" tall with a medium build with brown hair and brown eyes.
Anyone with information is asked to contact the Tinicum Township Police Department at (610) 521-3830 or 911.